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I drive my 1966 regularly. Today, with it fully warmed up, I had a sudden and unexpected total loss of the electrical system. Luckly, I coasted to the side of the road and when I opened the door I realized that even the dome light was out. I opened the hood and did the mandatory thumping of a few wires, battery cable, etc. I was standing there wondering what wrecker to call when it all came back on. I got in and drove home. Now I'm nervous about getting the car back out until I find what happened. I know there have been several similar posts about electrical failures but I'm not sure how to search for them. What should I check first?
I drive my 1966 regularly. Today, with it fully warmed up, I had a sudden and unexpected total loss of the electrical system. Luckly, I coasted to the side of the road and when I opened the door I realized that even the dome light was out. I opened the hood and did the mandatory thumping of a few wires, battery cable, etc. I was standing there wondering what wrecker to call when it all came back on. I got in and drove home. Now I'm nervous about getting the car back out until I find what happened. I know there have been several similar posts about electrical failures but I'm not sure how to search for them. What should I check first?
search for red wire problem on the forum and you’ll get pictures and directions on how to fix it. There’s a bad connection on the firewall connector where the large red wire connects kills the entire voltage except for the horn. The horn will still work if it worked before. You can either bypass it or you can try cleaning and tightening the connection at the bulkhead. There’s only one red wire in that bulkhead connector. It’s in the top left of the inside connector as you look at it from the front underneath the master cylinder that will definitely be your problem.
"Red wire" terminal in question is top left on inboard bulkhead connector. See pic below; tab of red tape adjacent the typically offending circuit. Examine both terminals at this location -- one on engine harness + it's mate at firewall.
Thanks for the suggestions. I can wiggle the connector and the power goes on and off. The pictures below show a broken connector on the opposite side you guys said contains "the red wire". How can I secure this broken connector short of replacing the entire harness?
By the looks of the ends of the harness where it enters the connectors, somebody has been in there before. That doesn't look like an original tape wrap at the connector.
If you'll do as I suggested and search the forum, you'll find instructions. Go to Google, type in "C2 red wire, corvette forum" and scroll to MANY posts to learn about it. If it was my car, and the pin on the bulkhead side was broken, I'd cut into the red wire on the engine side and run a new red wire through firewall and connect it with a ring terminal onto the connector post on the circuit breaker for the headlight doors. It's a quick easy, almost free permanent fix. The circuit breaker is on the driver's side kick panel. I'll attach a picture with the post circled to attach to. Then rewrap the bulkhead engine side plug so the replacement wire doesn't show. You'll never have the problem again if you make a good connection where you join the two wires.
To determine which post to connect the red wire to on the circuit breaker, disconnect one of the two red wires on the circuit breaker and measure which one has voltage on it (OR measure for continuity (short) any of the red wires on the horn relay OR battery + post). One wire goes to the rollover switch and the other to the horn relay through the bulkhead connector. Connect the new wire to the one that goes to the horn relay.
This is just to show you the post that the red wire connects to currently. All you are doing is bypassing that entire red wire pin in the bulkhead connector. Everything else in the car will remain connected and work exactly like it did before.
PS. Replacing the wiring harness will not fix the problem, unless you also replace the fuse box and associated wiring also. You'll be getting into quite a chore if you decide to try to fix it with new harnesses.
I had the problem about 10 years ago. I took it apart disconnect the battery got a soft bristle wire brush cleaned up the corrosion, got dielectric grease and made sure the connector was fully pulled out of both sides with a needle nose pliers. Put the connector back together and have never had another issue. With the tab broke off that is a whole other problem. I did a repair on a friend of mine 67 using a very small wire tie. It was not easy to find a place to get it through where it actually held it tight. But it can be done.
The engine side wiring harness is a Lectric Limited replacement harness that I installed maybe 12 years ago. I'm going to try the red wire bypass trick and tightening the connector with a zip tie. Thanks for all of the feedback
Bubba, yep. Butchered, yep. Repaired, yep. The Two wire ties tightened down perfectly and now both plugs ain't moving. I can kick both plugs without a loss of power. Sometimes, it's just what you have to do. And yes, I did cut the ends off the zip ties after the picture
Bubba, yep. Butchered, yep. Repaired, yep. The Two wire ties tightened down perfectly and now both plugs ain't moving. I can kick both plugs without a loss of power. Sometimes, it's just what you have to do. And yes, I did cut the ends off the zip ties after the picture
There's one other possibility that I didn't see mentioned, yet it's a common cause with the same result, if you happen to have a battery cut-off switch, especially those with the green ****, check it, over time the contacts oxidize and become intermittent, the "gate" type are better or none at all.
05-10-2024, 04:27 PM
Total Loss of Electrical System
Dennis
