Sharky II

I have several circuits that have a poor ground in my 1980. The battery is so cleanly wired I really hate to resort to this "cheat". I'm seriously considering running a nice fat 10 or even 8 gauge wire directly into the passenger area and into the dash to solve all these poor ground issues once and for all. Pros and cons of this approach anyone? I have a temporary 10 gauge wire rigged now and everything works. What am I overlooking here? I plan to install a small amp for the stereo down the road. So my days of one wire connected to each battery terminal are numbered. Hate to mess up a good thing and end up with a battery drain.

speedreed8

bradleyb66

I agree - I'd try to find the ground that's missing. However, if you want to add a ground, you don't need to go to the battery. The battery ground cable goes under the battery box and immediately screws to the frame. You can add a ground anywhere by simply attaching the wire to any point on the frame.

SwampeastMike

Have you disassembled and thoroughly cleaned the body harness grounds? If not, you really should. Only one is a true pain to reach.

The front lamp harness grounds in two places: on the underside of the front cowling between headlamp vacuum relays and the the lower-left (driver) corner of the radiator support bracket. The one on the radiator support is the difficult one but it can be removed and replaced using two universal joints, and a number of extensions to include a wobble extension or two. Such makes an ungainly assembly and it takes one person to guide on and keep the socket in place as the other turns. The engine harness ground is very near the starter--this one uses a machine bolt into a heavy casting so it's usually in much better condition than the others that use sheet metal bolts. The rear lamp harness grounds near the antenna. Clean the bolts, electrical connectors and mounting areas with a drill mounted wire wheel.

The cabin wiring harness ground near the headlamp switch is nowhere near as subject to corrosion and may well be in excellent condition. The power lock harness grounds on the inner metal liner of the passenger door. There is a bonding (strap) ground underneath the car very near the "B" body mount at the base of the driver side windshield pillar.

For some stupid reason the front turn/park lamps are on pigtails attached to the main harness. The connectors are not weather resistant. They get very cruddy and cause all sorts of strange problems.

After cleaning the grounds it's a good idea to clean every electrical connector under the hood--in particular the blower resistor and high-power connnections near the firewall on the passenger side. A combination of small wire brushes and a good cleaner work well. I ran out of contact cleaner and used carb/choke cleaner and it seemed to work fine. Just be careful and put a rag around the base of connectors/etc. to keep the cleaner from going places it shouldn't be. Also clean all exterior lamp connectors

While I did it at different times, I'd say it took at least two full weekends of work to clean all of my grounds. The improvements were truly remarkable. All lights are significantly brighter. The HVAC fan not only blows much more powerfully but it's significantly quieter. Wipers run more smoothly.

Sharky II

I have heard that. I usually prefer the engine block. I have done electrical work on cars but was intimidated with corvettes. Is the frame better than the block on C3 Vettes?

Sharky II

Thanks so much guys I really wish I could find a color code detailed wiring diagram 1980 c3 specific. Thoughts?

Richard454

Here's a wiring diagram for an 80 It's PDF format so you can blow it up.

http://www.keystonestatecorvetteclub...tte%201980.pdf

When I did my car- wasn't worried about how the factory did it- as they pinched pennies.

I got a bunch of pretty copper braided ground straps and added several to the engine and even the front radiator surround,

Compared to unibodies the frame is a great conductor- if it's not rusted badly. Copper-aluminum-silver-all conduct a lot better than cast iron- but we are talking chunks of it versus wire.

Running cables directly yo the battery will help keep noise out- as the battery acts as a big filter.

For my dash/ ECU/injectors/coil pacs/Vintage Air ECU- I have 4gu pos and neg cables running directly to the battery - 1//0GU is going to Alt and the starter

Sharky II

Richard, I thought to myself. (after I asked the question) Boy am I going to look like a Dumb-***! That would be redundant- The battery IS grounded to the frame. I talked to a guy who is a vintage Corvette mechanic. He also agreed that grounding some things directly to the battery works better. Where did you end up placing your fuse panel? Why did Chevrolet not just put it in the rear compartment near the battery? Many contemporary cars are done that way. Did you ever get that V-12 Jag engine swap finished?

Sharky II

Also Richard what do you think using about long battery bolts in stead of those gold plated screw in things with 1/4" of thread always strip out. the lead. I guess I could go to top posts. I just like the look of side terminals.