78 Electrical Issues

[Steve H.]

Restoring a '78 that been sitting in a Chicago garage for 15 years. Mechanical and engine issues resolved and it runs and sounds great. But there's a number of electrical/wiring issues: 1. GEN dash lit comes on and battery meter and tach stop working. Pull on parking lights and door chime starts. 3. When GEN light goes off BRAKE light comes on. 4. When I switch on rear defrost, heater fan cuts out. 5. If I step on brake with turn signal on, blinker light goes ballistic. 6. Horn not working. To name a few. I'm sure there are more so I'm looking at a comprehensive inspection.

Done what I can but electrical is out of my league. Can anyone recommend someone or someplace in northeast Georgia?

[David H.]

Re: 78 Electrical Issues

Steve,

Have you tried clean-up/inspection of all grounds? Poor grounds are often source of “weird” electrical problems. (e.g. step on brake and gas gauge changes, etc.

Dave

[Donald O.]

Re: 78 Electrical Issues

any mice been into the wiring?

Don

[Rick R.]

Re: 78 Electrical Issues

My guess would be mice or corrosion in one of the main connectors.

[Tom R.]

Re: 78 Electrical Issues

Done what I can but electrical is out of my league. Can anyone recommend someone or someplace in northeast Georgia?

I agree with "check with the ground" suggestion. My Pace Car electrical was acting goofy meaning sporadic. Checking ground straps first, I found that the ground strap from the starter to the frame had frayed as it entered the lug. Only a few strands remained to hold the cable to the lug. In a relatively short time, I had located the problem and just awaited the part.

I have a 1978 but I'm in Myrtle Beach and if you're in Northeast Georgia, I'm guessing you're up toward Anderson and Greenville, SC. I use a color-coded wiring schematic that is laminated made by Olsen Engineering. You might have noticed that Don Olsen responded above...and I suspect they are one in the same. This is an excellent schematic and easy to follow. Whether you do the work yourself or not, it should be part of your C3 documentation. I interchange its use with a 1978 Corvette schematic, I guess its an 11 x 14 schematic published with the Pace Car image on it...another excellent tool that not only shows the wiring schematic but includes components and their location. And I have the 1978 GM published electrical diagram that sits on the shelf. I have used these for tracking wiring issues, wire color codes, and even vacuum-related troubleshooting.

You may wish to contact both the Southeast Chapter and Carolina Chapter as their membership territory overlaps.