electrical problems on my 1990
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Joined: Nov 2020
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electrical problems on my 1990
hey yall, i got my carb swapped 1990 vette up and running a few days ago and there's a few small electrical issues that im trying to fix.
1. the tach needle climbs when the engine is turning over but once it starts the needle goes back to below zero.
2. the lcd display flickers and the backlight works but no discernable numbers show up even when its moving.
3. when i stop the car when the engine is hot and try to crank it over again to start it, the radiator fans turn on and draw too much power from the battery to move the starter
4. the right-side turn signal doesn't work, and neither does the arrow on the dash. the right side works perfectly though
any ideas on any of these problems. Electrical work is not my strong suit so any help is appreciated.
thanks
1. the tach needle climbs when the engine is turning over but once it starts the needle goes back to below zero.
2. the lcd display flickers and the backlight works but no discernable numbers show up even when its moving.
3. when i stop the car when the engine is hot and try to crank it over again to start it, the radiator fans turn on and draw too much power from the battery to move the starter
4. the right-side turn signal doesn't work, and neither does the arrow on the dash. the right side works perfectly though
any ideas on any of these problems. Electrical work is not my strong suit so any help is appreciated.
thanks
Racer
Joined: Oct 2012
Posts: 254
Likes: 34
From: Puyallup Washington
Hi. I would check the grounds and make sure everything is clean and connected solidly. Check that your engine block is grounded too. You'll find a bunch of grounds bonded together behind the battery on a block. It isn't the best spot for something like that since it seems like water intrusion is an issue there.
I was having problems with my dash lights fading, then they'd come on strong, then blink off or get very dim. The door chime sounded like a sick bird. The horns were anemic. My tachometer wouldn't work at all most of the time, or it would work on start then drop completely off. My door locks would hardly open or close. I finally had enough of it and dug into the issue one weekend. I found that all the grounds were terribly corroded and some had broken completely. I remade everything and purchased a small watertight enclosure that I mounted everything in with seals around the cables. I soldered the ring terminals and made sure everything was very clean. I also replaced every ground strap with new, braided ones. I replaced every bonding strap from the nose of the car to the back.
Since our cars have fiberglass bodies and other non-conductive materials, it makes grounding difficult. If you don't have good grounds, various loads will seek ground through other things like relay coils and lights, etc. and nothing will work right.
Anyway, I have a 1990 convertible and its problems are all resolved now as a result of my work on the grounding system. It wasn't very difficult once I got into it and it made a big difference. Contrary to what most people think, the ground path is really the most critical part of the power/charging system, but it often gets neglected. It may not be your issue but I'd start there if I were you.
I was having problems with my dash lights fading, then they'd come on strong, then blink off or get very dim. The door chime sounded like a sick bird. The horns were anemic. My tachometer wouldn't work at all most of the time, or it would work on start then drop completely off. My door locks would hardly open or close. I finally had enough of it and dug into the issue one weekend. I found that all the grounds were terribly corroded and some had broken completely. I remade everything and purchased a small watertight enclosure that I mounted everything in with seals around the cables. I soldered the ring terminals and made sure everything was very clean. I also replaced every ground strap with new, braided ones. I replaced every bonding strap from the nose of the car to the back.
Since our cars have fiberglass bodies and other non-conductive materials, it makes grounding difficult. If you don't have good grounds, various loads will seek ground through other things like relay coils and lights, etc. and nothing will work right.
Anyway, I have a 1990 convertible and its problems are all resolved now as a result of my work on the grounding system. It wasn't very difficult once I got into it and it made a big difference. Contrary to what most people think, the ground path is really the most critical part of the power/charging system, but it often gets neglected. It may not be your issue but I'd start there if I were you.
