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'79 L82, 4-speed, 15k miles. Looks like a couple of wiring harnesses need replacing. Here is a photo of two wiring harness connections to the driver's side engine compartment firewall. Which two wiring harnesses need replacing? What causes this? They are original. Also, any tips on replacing them are appreciated. Thx.
That's caused by over heated fuse panel/corroded connections, you're lucky it didn't catch on fire. Need to take apart and see what's going on between those connection and the actual fuse box. I bet fuse panel looks as bad. I would unhook battery now until you sort it out.
The dreaded goo only appears to have occurred at those wiring harness connectors... and on the red and black wires going into the Alternator. (see pic below)
Interestingly, the car runs great, and all electrical works normally.
Sure looks normal to me. When I replaced the wiring harnesses on my 68, the engine harness and the forward lamp harness had grease on them and were wrapped in plastic from the vendor. I believe it was used to keep moisture out of the electrical connections since they are down low in the engine compartment.
The goo could be factory sealant, although the application of the sealant was often a bit sloppier.
If you are having no electrical problems, I see no reason to replace the harnesses.
FWIW: in your pic, the left side is the engine harness; right side is the forward lamp harness.
Much appreciated, sullyman and EasyMike. It's interesting what new things one notices after all these years when cleaning or fixing things, and otherwise looking around.
I can think of NO reason why a car with only 15K miles on it would need to have any wiring replaced. "Time" [alone] doesn't really cause problems with wiring...unless there has been a major power short or a fire. Use, engine compartment heat (for 100K+ miles), current flow cause wiring age.
The insulation on C3 wiring is also pretty stout. Unless wires have seen excessive heat and current flow, they can usually be cleaned up with a wipe-down of lacquer thinner and a coating of polymer protectant for plastics.
If wiring has been 'boondoggled" by BUBBA to the point that you don't really know how things interconnect, maybe you need new wiring.
I can think of NO reason why a car with only 15K miles on it would need to have any wiring replaced. "Time" [alone] doesn't really cause problems with wiring...unless there has been a major power short or a fire. Use, engine compartment heat (for 100K+ miles), current flow cause wiring age.
The insulation on C3 wiring is also pretty stout. Unless wires have seen excessive heat and current flow, they can usually be cleaned up with a wipe-down of lacquer thinner and a coating of polymer protectant for plastics.
If wiring has been 'boondoggled" by BUBBA to the point that you don't really know how things interconnect, maybe you need new wiring.
7T1 - no short, fire or Bubbaing. Car is in excellent shape... and always fun to drive.
Good to hear the wiring is pretty stout.
I scraped some of the goo (sealant) from the base of the wires to see if the insulation is in tact, and it is. I just never noticed it before in the dark recesses of the left/front firewall. Thanks for the words.
Looked at pics on computer(phone earlier) and it does look like a goo... Just tore mine out and don't remember much if any sealant there I'll have to check again.
Heads up on the bulkhead connector, I had been having numerous come-and-go electrical issues with my 68, most annoying of which is loss of power to the coil. The car would just die and coast to a stop, then fire right up again and I was off. Finally after some recent engine work (cam change) I lost both the starter and coil wire... both dead. Drove me nuts.
Turns out the previous owner had installed new carpet and didn't trim the new carpet/gasket or whatever is behind the fuse panel. This kept the bottom of the connector from plugging all the way in, and you couldn't really see it from the top. It's very hard to see down in there anyway, even with manual brakes (no booster). FYI I had that same black slop all over everything, including inside of the connectors.
The way I finally figured it out was by removing the clip from the bolt in the engine side connector so I could remove the bolt. This way I could plug each side in individually to see how they were seating. Otherwise the bolt pulls the connector in and you really can't feel how its plugging in. I noticed the headlight harness seated very nicely but the engine side went in cockeyed. Cleaned up around the connector and it all suddenly plugged in and seated very nicely. Put the bolt back in and everything suddenly started working again.
When I took the bulkhead connector apart in my '79 the engine side looked like your picture. At first I thought it had overheated but then I found that it was some sort of original (I presume) goo with a bunch of dirt stuck in it. The same stuff is used on the inside of the connector as well.
They did use a nice heavy insulation for their wires so that isn't a problem. While the conductor sizes are adequate for their original load, there is very little leeway for additional electrical devices. I'd be willing to bet that most problems with the actual wiring come when people add additional accessories like stereo amps, extra lighting or higher powered headlamps without making appropriate changes to the wiring system.
Wiring Harness Replacement Q's?
