Wiring Issues

[6T8GTX]

I recently discovered that I have at least two burned up wires/connections on my 68 GTX. The wiring looks to be all original to the car. On the engine side the connection is burned on the N plug of the bulkhead connector. That's a dark blue wire w/ tracer from the IGN side of the voltage regulator. The plug above may also be affected (N - brown wire to the washer fluid pump).
View attachment 240359

The connection inside the plug on the voltage regulator also looks like it could be burned a bit.
View attachment 240360

On the inside of the car, the connection at point N of the bulkhead also looks burned.
View attachment 240361
That wire (dark blue with tracer) looks to run from the bulkhead to the ignition switch and from there to the oil light in the dash. It looks to be burned all the way to the ignition switch and perhaps beyond that.
View attachment 240362

I know almost nothing about wiring and it freaks me out, so bear with me. My questions are:

1. What would have caused this to burn? Age? Corrosion? Both? I didn't notice anything obvious like this when I replaced my old MP orange box ECU with a new one a year or so ago.

2. I'm assuming that cleaning the bulkhead connections won't be enough and that those wires need to be replaced at a minimum. Is that right? Do I also need to replace the bulkhead connector now?

3. At this point I'm thinking I should replace all of the wiring in the car but I don't know that I can do that myself and it will take me awhile to be able to get it into my guy. I'm assuming I can replace the wire on the engine side easily enough for a short term fix so I can keep driving it (16g wire with correct connections added). Should I also replace the voltage regulator and/or ballast resistor?

4. What about on the interior side? Is there anything I can do with the single wire that's burned that badly? Do I just need to get the entire dash harness?

5. Finally, the easy question - how do I remove the bulkhead connector? As I said, this stuff freaks me out and I don't want to make anything worse than it is or screw anything else up.

Thanks in advance.

JD

 

[Mogre]

I couldn't download your attachments. Had a similar melt down before I did the ammeter bypass. Check mad electrical upgrades for this circuit change. I ran a #8 wire from the alternator to the starter relay including 6" of #12 fusible link wire. I replaced all the damaged wires and the female and male connectors in the bulkhead. The bulkhead unplugs from the firewall on the engine side and then the other side is removed from the car interior firewall. Can't remember where I got the individual male and female bulkhead connectors. Always solder and shrink wrap all connections. Hopefully this will help as I can't see your pics.

 

[6T8GTX]

I'm not sure why the links didn't work. They do when I'm logged in, they don't when I'm not. Here the pics are again (in same order as listed above).

 

[Dako]

A couple hundred dollars will buy you complete re-popped wiring harnesses from Year One...with factory connectors. No messing with old brittle wires, just swap out the old harnesses with the new ones. Take plenty of pictures so you can see how to route the new harness like the original. It's so easy even a low brow, knuckle dragger (aka: a mechanic) can do it.

It baffles me that some would 'patch repair' old wiring that has already ' smoke checked' itself once. Is it worth losing your entire ride to an electrical fire? Not to me.

 

[dvw]

No need for a new harness. Melting is obviously cased by heat. heat is caused by either a short to ground(body) or by high resistance in the circuit (usually an poor terminal connection). The firewall terminals are poor at best. Add 40 years of corrosion and you get problems. The connectors can be sandblasted and filled with dielectric grease. If only a few cavity's are lightly damaged the connectors can be removed and a solid piece of wire run through the existing cavity ( you may have to run a drill bit through the cavity to clean it out. New Plastic hard shells are available . The good existing wires can be swapped and replacements fabricated for the damaged items. First you need to see what circuits are damaged. see wiring diagram here.
http://www.mymopar.com/index.php?pid=27
If damage is severe the firewall block can be removed and pulled back under the dash by depressing the clips and pushing it back through the inside of the car. Real bad damage may even necessitate dash harness removal. But you would have to do that if you were to replace it either way. Take your time. It's just like reading a road map. I just finished repairing my friends 68 Hemi RR.

 

[soundhd]

Your talking about a 47 year old car with 47 year old wiring.........that is a pretty scarey thought. My policy is anything over 30 years old in the way of wiring should be replaced. The main problem is the insulation gets very hard and cracks when bent which will cause the wiring to start to crack and eventually you will get a "partial" connection or swinging opens (the cracked wiring opens and closes when the car is moving) which can cause all kinds of problems including wiring over heating and causing fires. Best thing at this point (and no one really likes to hear this) is to replace as much of the wiring as you can. Does not have to happen all at once but the engine and under dash harnesses should be done first. That is where most of the problems start where fires are concerned. The forward light, cabin, rear lighting harnesses, etc.....can all be replaced as your budget allows.
As for keeping it all stock vs custom or aftermarket wiring is up to you. If you going for a completely stock look that is fine but if that is not a real big concern there are plenty of good aftermarket wiring kits out there that are a lot better material wise and will allow you to add more circuits for all kinds of options, engine options, (IFI, super & turbo charging, solid state ignitions), extra lighting, power options (seat, window) audio systems, etc......)...choices are endless. Hope this helps.

 

[red 69 runner]

M&H has all the harnesses you need for your car.I replaced every one in my car,a fire is not worth trying to save money.

 

[747mopar]

I'd ditch the bulkhead connector altogether! They are known to cause problems but if your wanting to keep it original I'd at least replace it and lube it up with a good electrical grease (I use copper never seize). Removing the bad wires and drilling out the connector to let the wire pass threw is a decent cheap option but I would be concerned with the rest of them too. I wouldn't even think about cleaning them up and re-using them, once a terminal has gotten hot it looses it's spring (clamping ability) so your just asking for trouble. Good luck

 

[dburnett6263]

All the info in the above reply's is good info. When I read your earlier post about turn signals, parking, tail, & backup lights, had bulkhead connector written all over it. I'm a EE by profession (that doesn't make me a genius) but 47 year old auto wiring that's been through countless cycles of hot, cold, humidity, & high current, is brittle and work hardened which in itself adds resistance & resistance draws current, current means heat, etc.,etc.
A repair of existing (MAD Electrical is good) is OK until the next gremlin shows up and another splice / connection is another point of resistance.
If your budget will allow replacement is the best and safest way to go. If possible ditch the ammeter for a voltmeter This keeps the current draw outside, less connections, and a shorter wire run.
You have something that many others wish they could have, don't take a chance on having a fire.

 

[6T8GTX]

Thanks for all of the replies and help, everyone. This site is the best. I'm definitely going to replace all of the wiring but because the car is basically all stock (with the exception of the MP electronic ignition), I'm going to stick with the factory system and running everything through the bulkhead (though I'll get a new one of those as well). Before doing that though, should I be trying to figure out whether the wires burned because of a short to ground? DVW suggested that above, as did someone else I was talking to. If so, how do you do that? I have a multimeter but I'm not well versed in it and will definitely need some guidance. Thanks.