Hello

There is a very large class of people that own 65/66 Mustangs that, as far as I can tell, anyway, have been, for the most part, ignored entirely. They don't really want that 100 pt. show car that is so nice and was soooo expensive that they're afraid to drive it, they also don't want to make their car capable of achieving warp factor three. They just want this car that they dearly love to be able to cruise around smoothly and reliably, without having it dump them out on the side of the road or have it start making weird noises or belching out big clouds of funky-smelling smoke. And I think, truth be told, that this is by far the largest class of Mustang owners. They take their car to some technician when what they actually need is a mechanic, and this, frequently, does not work out very well at all for the owner. They don't want to re-engineer the entire car, they just want someone to fix what broke. These are the people that I am trying help out with this blog. Some problems require a little bit of back and forth, as in, "Try this." "I tried that and it didn't change anything."
" Oh. well, you probably need to try that." " I tried that and it helped, but it still isn't quite right." "Now you need to try this...." If you go to http://www.allfordmustangs.com/ and then go to the classics forums, you will be able to do that with a pretty hefty gathering of some very knowledgeable people that also happen to be very friendly. None of that ridiculous one-upmanship, no flaming or abuse, none of that stuff. Just good, solid advice from people that know what they are talking about.

Thursday, April 3, 2008

Mustang Ignition system 1965 and 1966







Here is what your ignition system looks like without that pesky Mustang wrapped around it, along with the wiring diagram. This is a very simple system with a high degree of reliability, even when subjected to the horrible abuse and neglect some people inflict on these cars. How this works is, when the key is in the 'On' position, power goes from the ignition switch to the resistor wire, indicated by the red arrow in the bottom picture. This wire is plugged into a red wire with a green stripe that comes out of the ignition switch. When the power flows through the resistor wire, the voltage is reduced from 12V to about 9V by means of, that's right, resistance. The resistor wire ends at the firewall connector, indicated by the yellow arrow, and turns back into a red wire with a green stripe, which is attached to the post on the ignition coil marked either 'bat' or +, depending on the manufacturer of the coil that is currently in your car. That is the point indicated by the blue arrow. Inside the coil, the power is transformed from 9V to something in the 25,000 to 50,000 volt range, again, depending on the manufacturer of your coil. It sends this blast of power to the distributor by the big wire in the center of the distributor cap that looks like an extra spark wire. The rotor inside the distributor is spinning. The contact point on the tip of the rotor makes contact with the contact points underneath each of the plug locations of the spark plug wires as it spins around and sends that blast of current to the appropriate spark plug wire, which, in turn, causes the spark plug to fire.
In the picture of the distributor top without the distributor cap, the red arrow indicates the condensor, and the yellow arrow indicates the breaker points.
Here is how a breaker point ignition system works. The ignition system has two separate circuits in it. One, called the primary circuit, consists of the primary windings in the coil, the primary lead, which is the wire that runs from the Dist post on the coil to the distributor, the points, and then a path to ground through the casing of the distributor.The secondary circuit is the secondary windings of the coil, the high tension lead ( ninth spark plug wire that goes to the distributor cap), the distributor cap, rotor, and the plug wires. There are two different circuits inside the coil. How this works is power is supplied to the coil through the post marked Bat. When the key is in the 'Start' position power goes out to the starter solenoid through the wire attached to the S post on the solenoid. This closes the switch inside and sends power to the starter, and sends power out through the wire on the 'I' post on the solenoid, which meets up with the wire that goes to the bat post on the coil. Power goes into the coil, runs through the primary windings, out the Dist post on the coil, through the closed points, and then to ground. When the car starts and the key is in the 'On' position, power goes through the resistor wire plugged into the ignition switch connector, and out to the Bat post on the coil and, again, through the primary circuit. When the points open, that breaks the primary circuit, (hence the name 'Breaker Point Ignition' ) and the magnetic field that is built up in the primary coil windings goes through the secondary windings in the coil, and this produces the high voltage needed to actually fire the spark plugs. The high voltage goes out of the coil through the high tension lead, down into the distributor cap, through the rotor and out to the spark plugs, which are grounded through the threaded part of the plug. The points then close, which allows the current to pass through the path to ground through the primary circuit, and the coil builds up another shot of the high voltage for when the points open again. So, if the points are good, you will see a power reading from pretty much any metal part of the distributor when the points are closed, because the distributor is the ground for the primary circuit. If there is no power reading from the metal of the distributor, that means that power could not pass through the two contacts of the points, and that can't happen if the points are in a usable condition. Power makes it to one contact, but doesn't make it to the other = points are no good.If you have a power reading on the metal parts of the distributor when the points are open, that means that the primary lead is shorting itself out on the case of the distributor somehow, probably where it goes through that hole in the side of the distributor. The fix is to replace the primary lead and try not to scrape it up when it gets shoved through the hole in the side of the distributor. If the primary circuit checks out ok, but the plugs still aren't getting any spark, that is generally either a torched out distributor cap or rotor, bad plug wires or spark plugs that are fouled or just plain worn out. It's actually a pretty simple system once one understands how these components all work together to shoot sparks down to the plugs.

It is important that this system be properly maintained by means of a regular tune-up, which consists of replacing the spark plugs, distributor cap, rotor, points and condensor, along with inspecting the wiring periodically to make sure that nothing is damaged or worn out, or has a bunch crud or corrosion building up on a connection. These cars will keep on chugging down the road in an astonishingly poor condition, but it is costing you in a lot of ways to do that, namely, poor fuel economy and poor performance. Since all of the parts involved in this tune-up are really, really cheap, and readily available from any auto parts store, and the level of expertise needed to perform this tune-up is amazingly low, it makes no sense not to.

There is a problem that people encounter, which seems to be quite baffling to them, but results in 'car won't start'. If, when you turn the key to the start position, the car cranks fine, sounds like it started, but dies instantly when the key returns to the On position, that is almost always one of two things. Either the resistor wire is dead, and needs to be replaced, or, the car has a factory tach, and the tach has died. You could get a factory tach on these cars if A) you had a 65 or 66 Shelby GT-350, you purchased one of the over-the-counter Cobra or Rotunda tachs from your local Ford dealer, or your car had an original rally pac. How the factory tachs were wired was, two of the wires that came out of the back of the tach were connected in-line with the resistor wire at the ignition switch. You unplugged the resistor wire from the red wire with the green stripe near the ignition switch and plugged the two tach wires into the two ends of the ignition wiring. When the tach dies, it takes the car's ignition system with it. The fix is to unplug the tach wires and plug the resistor wire back into the red wire with the green stripe that comes from the ignition switch.

44 comments:

Terry Rogers said...

my 66 mustang tail lights come on with ignition switch and dim with dimmer switch?

Veronica said...

That's odd. Did the car just start doing that all of a sudden, or, has it done that since you bought the car? Also, when you say 'dimmer switch',do you mean the headlight dimmer switch that's on the floor or the knob on the headlight switch that dims the instrument lights.

D Freit said...

Hi Veronica,

How would I go about finding the factory tach?

Also, Could you get more into detail on how to fix the tach by connecting the wires you speak of? I am having the problem of the car starting up, but then instantly dieing or not wanting to continue to run. I think my tach may have gone out? (I am running a rebuilt motor and also have electronic, not points)

I will check the resistor wire, but how would I do so? also, how would the repair go to fix the resistor wire?

D Freit said...

Hi Veronica,

How would I go about finding the factory tach?

Also, Could you get more into detail on how to fix the tach by connecting the wires you speak of? I am having the problem of the car starting up, but then instantly dieing or not wanting to continue to run. I think my tach may have gone out? (I am running a rebuilt motor and also have electronic, not points)

I will check the resistor wire, but how would I do so? also, how would the repair go to fix the resistor wire?

Veronica said...

As far as checking the resistor wire goes, all that you need to do is turn the key to on position, disconnect the wire from the 'bat', or (+) post on the coil, depending on how your coil is marked, and check to see what the voltage is at the connection you just removed from the coil. That should be something in the 6 to 8 volt range.

The tachometer is not hard to locate. If you have one, it will either be one of the gauges in a rally pack attached to the steering column or, a free-standing gauge mounted to the dash or possibly the steering column. You would not be fixing the tach by connecting those two wires. What you would be doing is bypassing it. If it has failed, what you would be doing is bypassing what is functionally a great big blown fuse.

Jeannie Keeney said...

Veronica,

We bought my son a 1966 mustang, ran but sounded like it needed some TLC. About a month ago it got to where it would not crank. We bought a carburetor kit and my dad rebuilt it but that still did not help the problem. It will turn over and crank but when you release the key it will die. We replaced the solenoid, ignition switch,condenser and points. Still would die when you let off the key. My dad ran a wire from the battery to the coil, we turned the key and it cranked and stayed running. So we are thinking the pink resistor wire is bad. Does this sound right and how do we replace and or check it. We also tested the solenoid and it read 10 on the meter on both sides. We traced the Pink resistor wire from the ignition switch to the firewall and on the other side it becomes a brown wire to the coil. Any help would be greatly appreciated.

Veronica said...

You are definitely on the right track. That brown wire that goes to the coil is supposed to be red with a green stripe. It sounds like someone might have spliced something in for some reason. People do funny things to their old Mustangs. What you are supposed to have is a brown wire and a red/green wire coming out of the same place on that connector. The brown wire is supposed to go to the 'I' post on the front of the starter solenoid and the red/green wire goes to the positive or 'BAT' side of the coil. A failed resitor wire will cause all of the symptoms that you describe, but, I think that what you have going on is just some wires going to the wrong places. I would first check the wiring that I had on the car against what is shown in the wiring diagram in the second picture and make sure that everything was going to the place that it is supposed to.

Don A. said...

Hello Veronica,

I have a 65 C Code 289 2V. No big changes except for Petronix Ignitor.

I have no spark and have been reading all of the forums.

With ignition "ON" I have 12.4 volts at the Coil+ end of the wire but when I attach to the Coil+ terminal along with red petronix lead, the voltage drops to 5.5 - 6 volts DC.

Any thoughts?

Thanks in advance.

Don A. said...

Hello Again,

So, I tried an old coil that came out of the car 8 years ago. (I get heck because I do not discard old parts). Guess what? It runs perfectly. So, my question is, is too much voltage getting to the coil? When ignition is on, there are 12.6V dc at the end of the wire going to coil+. When I actually connect the wire to the +side of the coil, along with the red wire going to the Petronix Ignitor and the -VE wire from the Petronix is attached to the -VE side of the coil, the voltage reading on the +ve side is 6.6v dc. Is there something wrong and will I burn out this old coil as well.

Thanks for any insight and help you can provide.
Don

Veronica said...

Weirdness like that is why my car is running on breaker points instead of Pertronix. I had one of those things in my car a few years ago, but I never really trusted it, and I kept hearing stories like yours. I always kept the points and condensor in the glove box for 'just in case', so, I just went ahead and put the points back in.

As far as the 6V when the wire is attached to the coil, it's supposed to do that if you have not bypassed the resistor wire. It could be that the coil that wasn't working right has died on you,but, I really couldn't say anything for sure without having the car sitting right in front of me. If it was me, I would run the coil that works until it quit working, and have a spare in the trunk that I knew worked also. The coil that you have might go for years.

As far as hanging on to old parts goes, I'm that way, also. But, take heart. Eventually people come to accept that this is just who you are and let it go. I haven't had anyone try to give me grief about all of these parts stacked up everywhere for a while now. My husband will start poking at me about it occasionally because he seems to enjoy doing that, but, nobody else does.

Indysam said...

I have a66 that was running. I think we may have shorted something. The horn button? Is not on the car. While car was running, my son touched the horn button to the steering column, trying to figure out how it attaches. He says he saw a spark. The car died. Now we have NO electrical
No headlight, no courtesylight, nothing.
Any suggestions?

Indysam said...

My 66 has no electrical at all except battery is good. Power to yellow wire at firewall (engine side). Car was running, think I may have shorted something. Also the pink resistor wire has a white connector near ignition switch . In messing around trying to find why no electrical, white connector is damaged. Can I splice pink wire to red/ green ?

Veronica said...

As far as the connector on the resistor wire goes, yes, you can splice that into the red/green wire. It's supposed to be plugged into that anyway.

Momentarily shorting out the horns shouldn't kill the whole electrical system. The horns draw power from the headlight switch, not the ignition switch. Since everything died at once, the way to figure out what happened would be to start at the black wire with a yellow stripe that is attached to same post on the starter solenoid as the positive battery cable and follow that in stages with a volt meter to find out where the power is stopping. You can cut that task in half by unplugging the headlight harness and checking the other end of that black/yellow wire with a volt meter. If it does not show power, the problem is in front of the firewall, in the engine bay area. If it does show power, then the problem is inside the car, behind the dash.

Japheth Willmore said...

I have a 1966 mustang and am having issues starting the car. We replaced the engine and reinstalled the wiring. After playing around I got the car to start. The next day when I went to start the car nothing would happen. The car doesn't even roll over. What do you think may be the problem?

Veronica said...

Based on what you have said, it is an extremely long list of things that could be the problem. I would start with running a wire from the positive battery post and touch the post on the front of the starter solenoid that is marked 'S'. It should have a red wire with a blue stripe on it. If that makes the car crank, which it should, I would disconnect that red/blue wire and see if it showed power while a friend has the key in the start position. If no to power on that wire, the problem is somewhere along that wire between the solenoid and the ignition switch. If the car has an automatic transmission, that wire goes through a neutral safety switch, which also could be the problem. Check those things and let me know what you discover.

Gator said...

Wow Mrs. Veronica, you know an impressive amount about these old stangs! let me riddle you this ... 2 problems 1. my 67 stang will not run.its not producing a spark from the coil. i have replaced the coil and condenser. points are the last thing i need to change. im getting 12.4v to the coil but nothing coming from the coil the the dist cap. ....2nd issue the original motor was a 289 ,when it blew up the po installed a 302 jasper crate motor.the car has sit for the last 10+ years. the problem is when i turn the key ,the starter spins but is not making a the proper contact with the ring gear. when i removed the starter i examined the ring gear and saw that the front (engine side) of the teeth were a bit chewed as if the starter is not fully engaging. so i took it to the part store and had it checked. i can see the starter fully extend out to the end of the housing... i bought a new starter bc it spun a lot more faster. when i installed it ,i had the same results,spinning but no starting. it finally did catch the flywheel and turned over the motor. but its hit or miss.
i do believe that the first issue can be fixed with a new set of points and adjustment but the second issue worries me. is the 289 and 302 starter different? i know the autos came out with a long nose starter and the manual came out with a short nosed starter. mine is a 3 speed . thanks so much for any ideals on my problems!!

Veronica said...

Thank you, that is very kind of you. The problem with trying to figure out what's wrong with a car that has a mix-n-match configuration installed by the dreaded Previous Owner is that you can't really tell what it is, exactly, that he has done. I would check and see if this was the original bell housing first, and then I would try to figure out which flywheel he has on there. If the motor came with that flywheel, then maybe it's mentioned in the paperwork on the motor. However, typically in these situations the aforementioned Previous Owner has thrown away all of the paperwork years ago. If that is case, and the starter teeth seem to be getting chewed up on the front end, I would wind my nerve spring up as tight as I could and stick a long nose starter in there to see what it did.

On the no spark thing, I would disconnect the lead from the coil to the points at the distributor end, turn the key to the on position and see if I got power at the distributor end of that wire. If yes, I would go ahead and replace the points. If no, then I would disconnect the wire from the positive side of the coil and make sure it showed power. If yes, the coil is bad, if no, the problem is between the coil and the ignition switch. Let me know what you find out.

MrSwmarlow said...

65 mustang. I finally got it to crank after I sorted out the mess the previous owner left me, but it will not run. May have to do with the pink resistor wire to the red/ green stripe wire connection or wire to the coil.???

MrSwmarlow said...

65 Mustang after sorting out the wiring mess from the previous owner I did get the motor to turn over but will not start ??? resistor wire to red/green to coil I don't know ? Thanks

MrSwmarlow said...

66 mustang, turns over not starting. Resistor wire issue to the red/green stripe??? I do not know. Thanks

Veronica said...

The dreaded Previous Owner strikes again. There are all sorts of things that make a car crank, fire up, sputter and then die. You will need a volt meter if you don't already have one. I would start by turning the key to the on position and check to see if I had voltage at the post marked 'I' on the front of the starter solenoid. If that shows voltage, I would then disconnect the wire from the terminal on the coil that is marked either "BAT' or '+', again turning the key to the on position and see if the wire that I just disconnected (red/green) showed power. If it does, I would reconnect it, pull the distributor cap and have a look at the points. If they look ok, the gap is about right, etc... I would put everything back together, pull a spark plug, put wire back on the plug and, holding the plug with some insulated pliers, ground the plug out on a valve cover bolt or something while someone cranks the motor as if trying to start it. If that shows a good spark, you could have a fuel delivery problem, like the carb needs to be gone through, a clogged up fuel filter, maybe a a problem with the fuel pump, etc.. Let me know what you find out.

Gary Lovelace said...

My 65 mustang 289 will periodically sputter and shut down then spit and backfire when you try to start it again. I replaced the distributed, coil, wires and plugs and the problem kept happening. I finally realized that though the resister wire shows resistance I was still getting 11 volts to the coil. I put an extra resister in which brought it down to 9 volts and everything cleared up until today when it sputtered a little and then when I went to start it again she started doing the whole sputter backfire thing again. I unplugged the wire from the starter solenoid and it started fine. Why would my ignition periodically not like the 12 volts when the car is designed to provide 12 volts when starting? Also when the car is running and I touch 12 volts to the coil it kills the engine. What could cause it to be so sensitive to voltage?

Veronica said...

The answer to a couple of quick questions would help out a bunch. First, which wire did you unplug from the starter solenoid? Also, is your ignition system in basically stock configuration, as in,a stock distributor that had points inside it, no MSD box, etc...?

Gary Lovelace said...

The ignition is stock but new with points. I unplugged the right wire which goes directly to the coil. I tested it to make sure it was right and that it wasn't shorting out anywhere. There is no power at this starting solenoid terminal when engine is running. It shows about 13 volts when cranking. It seams that the extra 13 volts causes problems sometimes. If I jump a wire directly to the solenoid with no resister the engin will die and won't start. I purchased a new coil with no change. Even with this wire unplugged it loads up sometimes. It runs great but will stumble periodically. I have become quite baffled by the problem. Before I removed the wire to the solenoid it was really hard to start. It would backfire, shake and barely start. I replaced the whole ignition system except cab wiring. Then replaced fuel system including carb. That didn't' work so I overhauled the engin and replaced the timing chain and gears. Engin looked great but still had the problem. Would run sometimes but rough and was really hard to start. I finally put the extra resister in and it started running really good. After a couple days it died and was doing the same thing when I would try to start it. Being that my new clue was voltage I thought that maybe the extra 13 volts was causing the problem. I pulled the plug on the starter solenoid and it started up no problem. I don't understand why it can't handle the extra voltage. Also as I mentioned it has a little flutter. I put a volt meter on the wire going to the coil and I noticed a fluctuation between 6 7 8 volts. When I first installed it it was showing 9 volts. Do you think these fluxuations could cause the coil to fire erratically and are these fluxuations normal?

Veronica said...

If everything is as it should be, the car would not start with that brown wire on the 'I' post of the starter solenoid unplugged. When the key is in the Start position, power goes to the coil from the starter solenoid along that wire.If the car will start with that wire unplugged, the coil must be getting power from somewhere else, which would just about have to mean that you have a short in the ignition wiring somewhere. I think that I would snatch the instrument cluster out and have a look at the wiring coming out of the back of the ignition switch. If that seems to be ok, I would also remove the connector from the back of the ignition switch and have a good, close look at that. That would at least be a good starting point, anyway.

Gary Lovelace said...

Thank you. I started suspecting that. I unplugged the pink wire from the ignition switch and plugged in a new non resisted wire. I ran this wire directly to the coil and purchased a coil with an internal resister. She runs great now. This makes sense because I believe the radio has a short in it. I didn't think about the radeo being on the same wiring because the wiring diagram doesn't show it but it may be since its part of the accessory wiring. Not sure but I unplugged it as well. Anyway it seems the issue is solved and this could be the same problem with the original posters car.

Barbara Bower said...

Hi Veronica, we could use some advice. 1964 1/2 289 4V with a rally pack that had an ignitor II and a flame thrower II coil when we got it. We've had some trouble and decided to put in a replacement distributor with points/condenser but kept the coil. Tested the resistor wire per your direction and we're getting 12V at the coil.

We have an RU4 resistor block(like this http://www.summitracing.com/parts/smp-ru4?seid=srese1&gclid=CKWmrKaa98YCFYwYHwodP88LLw)we tried putting after the tach and before the existing resistor wire. Still getting 12V before the + connection on the coil.

Now I'm wondering if it's a valid replacement or if we need to just replace the resistor wire? Or do we even need a resistor wire with the flamethrower II coil?

Veronica said...

Since you are running the points/condensor set-up now, like the car came with, you definitely want to have a functioning resistor in there. The full 12V would cause both the coil and the points to fail prematurely. The cleanest way to accomplish that would obviously be to just replace the resistor wire, but, I'm not sure if anybody still sells that resistor wire by itself. It used to be that you could buy them at the parts department of a Ford dealership, but, they might be out of them by now. Another way to go would be to put a resistor block from an old Mopar, like 69 Challenger or Road Runner, under the hood, but, if this is a car that you take to shows, you would have to put that behind the dash somewhere, and those things get pretty hot when the car is running. The advantage of the resistor wire is that it spreads that heat out over the entire length of the wire, instead of concentrating it in that one little resistor block. Let me know if you have trouble finding the resistor wire, if that is the way you decide to go, and I'll see if I can find someone that has one of them.

nelson said...

I have just purchased a beautiful on the outside 65 Mercury Comet. Unfortunately to start it the previous owner used a wire from the battery to the solenoid to provide what the ignition switch would normally provide in the "on" position. Therefore I need to lift the hood every time I start or stop the engine. The wiring in general has been cut apart and reassembled many times. I am planning on a complete new wire harness over the winter but I would like to drive it a little now. After reading the posts and comments here I believe that the resistor wire is bad. If I were to apply power to the pink wire coming out of the column connector from a neighboring wire with continuous power and the car starts and stays running then would that mean that the resistor wire is shot?

Veronica said...

Does this starting procedure go something like you open the hood, run a wire to the post marked 'I' on the starter solenoid, then go inside the car and start the car with the key in the usual manner, and then, when you arrive at your destination, you turn the key off, and then go disconnect the wire from the starter solenoid? If that is indeed pretty much how you've been doing it, I would unplug the resistor wire from the red/green wire coming out of the back of the ignition switch, plug a new length of wire into that, and run the other end out to the positive side of the ignition coil. If the car will start and run normally like that, then the problem is somewhere between where the resistor wire plugs into the red/green wire coming out of the ignition switch connector and the coil. The problem could be the resistor wire, or, it could be the big plug-in connector at the firewall. If you look at that connector and find where the red/green wire comes out of it on the engine side of the firewall, you will see that it looks like there is also a brown wire coming out of that same location, and, that is exactly what is happening. The reason for that is that, when the key is in the 'start' position the red/blue wire on the post marked 'S' on the starter solenoid brings power from the igition switch to the starter solenoid. That activates the solenoid and power goes from the battery, through the solenoid and then to the starter. Some of that power is diverted from the solenoid, through the brown wire, which is spliced into the red/green wire at that firewall connector, and from there, it goes to the coil through the red//green wire. If those two wires have gotten themselves cut off from each other because of af age, corrosion, etc.. the car won't start. If, when you try to start the car, it just cranks and cranks and never fires, the problem I just described is far more likely to be your problem. If, on the other hand, you try to start the car with key, it sounds like it started, you release the key from the start position, and the car dies instantly, that is a problem with the resistor wire, assuming that you have already run the test I mentioned by plugging in a new wire from the switch to the coil. If you haven't run that test, the problem could also be the ignition switch or the big connector on the back of the ignition switch. That test would either eliminate those two candidates or confirm that it is one them that is causing the problem. Let me know what you find out.

Barbara Bower said...

Veronica - I found a post on allfordmustang forum with NAPA part# ECH ICR 22 that appears to be the right replacement for the resistor wire. It tests at about 1.5 ohm. We took the rally pac out of line so it's hooked up red/green directly to the pink resistor wire, crimped to the cut end of the old resistor wire at the firewall. The red/green end at the coil is still testing at 12 volts.

We had previously replaced the ignition switch and the red/blue wire in the dashboard wiring harness because it was melted.

Your previous post had said it should be down around 6 or 8 volt on the red/green at the coil, correct? Any idea what we're missing?

Veronica said...

If what you have is a short run of red/green wire coming out of the ignition switch connector with one end of the resistor wire connected to that, and the other end of the resistor wire ends where the red/green takes off through the firewall to the coil, and there isn't something strange going on like another wire paralleling the resistor wire and meeting up with the red/green before it gets to the coil, then, you have it wired up correctly. In other words, there is one wire going straight from the ignition switch to the coil, with the resistor wire being one section of that one wire. If that is what you have, I don't know what the problem would be, but, it isn't with the way that you have the wiring. The only thing that I could think of is that the brown wire from the starter solenoid has figured out a way to backfeed 12V to the red/green wire at the firewall connector, which would indicate a starter solenoid problem. I would unplug that brown wire and see what sort of readings I got, but, it would be really, really strange if that actually was what was happening.

nelson said...

Hi Veronica,

Thank you very much for your detailed comment. I got sidetracked with replacing the steering rack which should have been straight forward but has been a challenge at best.

I did use an Ohm meter on the ignition switch and found out it was bad so I replaced it. Now that I am waiting on a new exhaust manifold for the steering problem. I will try the wire test this weekend. BTW your description of the driving/starting procedure is spot on.

I will let you know next week what I came up with.

Thanks again.

Lance Peck said...

I just recently purchased a 64 1/2 with the 170i motor, and am having problems with getting the engine going. The engine turns over, but doesn't start. I am not getting a spark at the plugs. I purchased new points, distributor, and rotor but still nothing. i am getting around 5.4 volts on the coil when testing it. Any suggestions on what could be the problem? I have read a couple of other forums and blogs, but wanted to ask because you seem the most informative. Thanks for any help you can provide.

Lance Peck said...

I just recently purchased a 64 1/2 with the 170i motor, and am having problems with getting the engine going. The engine turns over, but doesn't start. I am not getting a spark at the plugs. I purchased new points, distributor, and rotor but still nothing. i am getting around 5.4 volts on the coil when testing it. Any suggestions on what could be the problem? I have read a couple of other forums and blogs, but wanted to ask because you seem the most informative. Thanks for any help you can provide.

Veronica said...

You are too kind.
If you could answer a couple of quick questions, that would really help out a bunch. First, has this car been like this since you got it? And, when you installed the new points, did you also get a new condensor?

Lance Peck said...

Thanks for the quick reply back. I just purchased everything new because it was sitting up for 10 years. The points looked pretty bad. The only part that i wasn't able to get new was the condenser. New coil, plugs, wires, rotor, cap, and points. Ive read it could be at the ignition with or the resistor wire, I'm getting some voltage so wasn't sure what the my next approach should be. What color are said wire, and what are your thoughts? Thanks.

Veronica said...

Strange. Here in Texas, that condensor is readily available at any major auto parts chain store. I would definitely try to track that down somewhere. I'm assuming that you checked to see if the coil was getting power by just turning the key to the 'On' position and checking with a volt meter. When the key is in the 'Start' position power goes to the coil from a different place than when the key is in the 'On' position. For starters, I would have a friend attempt to start the car will I checked the post on the starter solenoid marked 'I' which has the brown wire on it to see if it showed power. A problem with the resistor wire would not make the car not get power to the plugs while cranking on the starter because the resitor wire is bypassed when you start the car.

Lance Peck said...

Ok I got a chance to check solenoid. I'm by no means an electrican so hopefully I used the voltmeter the correct way. I came up with 5.6 volts through the solenoid with the battery on. When the car was cranked it went down to .7 volts and stayed around there. I felt the solenoid after cranking and it was very warm to the touch. Is that that proper volts or should it be sending 12 down the pipe?

Veronica said...

No, the car is supposed to be getting the full 12V when starting. Just to make sure, I would pull the brown wire off of the post marked 'I' on the front of the solenoid, have the aforementioned friend crank the car, and check the post on the starter solenoid to see what the voltage is when cranking. It is supposed to be 12V, but, if the battery is not all that it could be, the voltage might drop a little. If the car will crank, it should be at nearly 12V, though. If it actually does drop down to point something volts, you need a new starter solenoid.

Lance Peck said...

Thanks, gonna try your suggestion today or tomorrow and will post results

Lance Peck said...

Got a new solenoid and finally was able to crank it. Showing 12 volts in the on position, and when cranking very low voltage. Took off the brown wire and also nothing.

Dana Facemyer said...

I have a 66 mustang with a 289. I put in new points and it ran great for a short amount of time. Then turned rough - (10 min of driving). Brought it back in the garage and put in new points since the other was charred (way too fast). After other diagnostic efforts I found out wires 6 and 3 do not produce a spark to the plug. I put in new cap and rotor, switched wires to see if it were a faulty wire but the wires work fine and put in new spark plugs. Still no spark out of wire 6 and 3. The rotation of the wires is 15426378 and I find it odd that the two numbers next to each other are producing a spark out of the wire.

Veronica said...

I think that I would start by checking the point cam of the distributor to make sure that the points are actually opening for numbers 6 and 3. It could be that a slightly bent shaft in the distributor could make those positions not open the points, or, it could be that 50 years of use has worn them down. If you rotate the motor by hand and stop on each lobe of the point cam and check the point gap, that should tell you something useful, one way or the other.