Where do you smell the burning from? Under the dash?

I wish I had a decent diagram. You wiring system is pretty basic compared to mine.

Can you take some picutres?

Go one step at a time. If you melted some wires you should have also blown the fuse for the circuit. Look at the fuses.

Look specifically for melted wires up under there. Don't pull it apart yet. Take your time.

Turn the key to on. Watch everything. What specifically is not working. Example do the gauges move? Does the radio work? Does any instrument flicker?

It will in all likely hood be two wires making contact.

Jim

 

Well this is what I've deciphered so far. I have a purple/white wire coming from the ignition switch. Thats what was burning. It started melting. I think Bubba has been here. That wire goes to a plug that has been jumpered out. Once it leaves that plug, there is a t-tap. One wire goes back up in the dash and the other wire goes towards the firewall. I don't know if the one through the firewall goes through the fuse block first or straight through. I'm showing a dead short on the purple/white wire, to ground.

 

I do have power. If I turn the key, the gauges and radio do work.

 

I have a crappy diagram but from what I see.From the ignition switch one wire runs to the starter. The other wire runs to the positive side of the coil. Another wire runs from the positive side of the coil to the starter completing the circuit.

So the wire you are looking at is the one that either goes to the starter or the coil.

Does it go through the panel or direct??? I don't know on yours. Is the starter fused? Is the coil fused?

One thing is for sure. If you checked for continuity you should have it at either the starter or coil on that wire.

Can anyone here post a wiring diagram?

Jim

 

I found another diagram. So the purple (diagram shows solid purple) goes to a white/red/black (referred to as the resistance wire). It should be white/red/black at the coil. On the same side of the coil you should have a yellow going to the starter.

There should be two wires coming from the ignition switch. what color are both? Is the a solid purple in addition to the one you mention?

Jim

 

I have a wiring diagram but its not the best. The wire that burned is the wire going down to the starter, to start the car. I'm reading a dead short to ground on it but I think I need to disconnect it from the starter to get a good reading. It may read grounded through the starter. I can't tell whats fused and what isn't. It's such a mess under there. It looks like it goes behind the fuse block, but I don't know if it goes through it or bypasses it. It comes out through the harness on the firewall.

 

I found the resistance wire and the wire from the coil to the starter. They are good. My problem is the wire that goes from the ignition switch to the starter

 

The purple wire is connected to a number of things. It is run to the "S" terminal on the starter solenoid and it's purpose is to power the solenoid for engine starting. It is coming from the clutch safety switch (if you have 4-speed) or the neutral safety switch (if auto), and it originates at the ignition switch. That wire is reading a short because it connects to one side of the solenoid coil; the other side of that coil goes to ground. You should not be reading "0" ohms, but low ohms. Remove that wire from the "S" terminal and measure again. If you still get continuity to ground, the purlpe wire is shorted somewhere else (wire insulation rubbed through at clutch pedal or bad ignition switch [unlikely, but possible]. Start removing the purple wire from its components{as mentioned above} using the ohmeter to find when the 'ground' signal gets disrupted. Start by pulling both connectors on the clutch safety switch. If 'ground' is disrupted, then the safety switch, the wiring near it, or the ignition switch is the problem. If you pull those wires and you still have 'ground' signal, the wire running from the safety switch through the firewall is shorted somewhere. Work toward the ignition switch, if you are still showing 'ground' signal present. You will eventually isolate the area where the ground is originating in that wire.

 

OK I'll give that a try. Thanks to all the people that posted to help me. I appreciate it alot. I'm off to the garage to see what happens. Thanks again.

 

I don't think its fused. But you may have a fusible link somewhere. I think in the older cars the fusible link is the wire. Its goes from a higher gauge (thicker) to a lower gauge (thinner) wire as it nears the starter.

If you are confident about what you are doing you can bypass the entire wire. Run a new wire from the swirch to the starter.

My guess is the the wire has melted somewhere. Thats what its suppose to do, it acts like a fusible safety link.

That real question is what did you do to cause this? Did you cross a wire when installing the coil? Did you skin a wire when you installed the new air cleaner or bent back the coil bracket?

Pictures would help.

Jim

 

I just had my starting system completely apart last fall. Based on what I learned doing that, the above is exactly correct, and well written. Bubba is very fond of jumping the clutch cut-out switch, with some good reason. When diagnosing the system, it is an easy way to eliminate one component. But, it is a lot easier to grab a hold of the connector and get it off than it is to get it back on properly. I had to take my driver's seat out to get the thing back on.

Don't give up! Let us know how this worked out. I suspect that this purple wire problem is not the only problem in the system, but get this one straightened out and see if your backfiring/blowback problems still exist.

 

I have to take a break from it for a couple days. My temper is getting the best of me. This car is amazing. It hasn't actually been on the road in over three years but I only had a few things to fix. Everytime I fix one thing, two more things break. I tried rebuilding the brake calipers and they leaked worse than when I started. I finally bought the o-ring rebuild kits from VB&P and they are good. Then the temp gauge stops working. In the process of trying to fix that problem, I notice that the pinion seal is leaking. Then I have the problem with it running crappy and the wires burning. I'm thinking she just doesn't want to be on the road. Hopefully I'll calm down enough to work on the ignition wire and backfiring problem this week. Thanks again for all the help. I'll let you know what happens.

 

A couple of days break sounds like a good idea. I went through the starting circuit in the fall, but haven't delved into the ignition circuit on a Corvette since I sold my '69 (1995), so I needed a few lessons from the folks in tech/performance yesterday, and now I feel better.

To comment on your question of why the resistance wire would show a "short to ground" with the key in any position, I would need a definition of what you mean by "short to ground". If by that you mean that you are setting your multimeter to resistance and touching one lead to the wire and the other lead to the block (or some other good ground) and you are getting low resistance, this should happen any time the points are closed, regardless of the position of the key. If I was concerned about that, I would take the distrib cap off and see if the points are closed. If they are, I would rotate the engine slightly until they were open, leave the key in the off position, and test the continuity again. If you get no continuity, then you will know your resistance wire is not grounded out. If you are still grounded, you have a short in the primary ignition circuit before the points.

Let us know how it works out.

PK

 

This check won't be valid, the gauges are hooked up to the same wire after the ign switch in the cab, it is going to allways read low resistance to ground. The points may alter the resistance from dead short to some low reading though.

 

I figured the points would be isolated since I was reading a short to ground, with the resistance wire disconnected from the coil. I'm thinking the resistance wire is fine, but the melting ignition wire is the problem now. I'm going to run a wire straight from the battery to the starter solenoid, and see if it turns or burns. If it turns over, I'll just run a new wire to the starter for now. I'm going to start working on it again tomorrow. Thanks for all the help. I'd be lost without this forum.