C4 corvette Light/electrical problem?
Thread Starter
Heel & Toe
Joined: Nov 2024
Posts: 17
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C4 corvette Light/electrical problem?
I have a 1984 corvette that uses to be a crossfire injection and was converted to a carburetor and it seems part of the wiring harness that went to the crossfire system was just chopped off. When I brought the car home it had no problems the digital gauges worked courtesy lights worked headlights and taillights worked, but the engine was junk so I built a new one and put it in the car, now I have the problem of low voltage or something, when I got the car on the road for a test drive the digital dash started working again and so did the courtesy lights. But when I hit the brakes the dash gets really dim and if I try to turn on the headlights the light for them comes on on the dash but they don’t flip up and the dash also gets very dim. I’ve been chasing this issue for over a week and I’m getting really tired of this because I can’t drive it like this, any idea what the problem is?
Thread Starter
Heel & Toe
Joined: Nov 2024
Posts: 17
Likes: 0
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,497
Likes: 3,999
From: Cape Coral, Florida
I have a 1984 corvette that uses to be a crossfire injection and was converted to a carburetor and it seems part of the wiring harness that went to the crossfire system was just chopped off. When I brought the car home it had no problems the digital gauges worked courtesy lights worked headlights and taillights worked, but the engine was junk so I built a new one and put it in the car, now I have the problem of low voltage or something, when I got the car on the road for a test drive the digital dash started working again and so did the courtesy lights. But when I hit the brakes the dash gets really dim and if I try to turn on the headlights the light for them comes on on the dash but they don’t flip up and the dash also gets very dim. I’ve been chasing this issue for over a week and I’m getting really tired of this because I can’t drive it like this, any idea what the problem is?
Sounds like a ground issue with dim dash…not a low voltage issue…sorry don’t have wiring schematic for an 84.
Thread Starter
Heel & Toe
Joined: Nov 2024
Posts: 17
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My car dosent have a ground strap from the block to the transmission or from the block to the frame, Chevy trucks I’ve worked on have had these do I need those on the corvette too?
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,497
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From: Cape Coral, Florida
Well what you can try is if you have some jumper cables connect between the block and the frame and see if the lights still dim…if you have a DVOM connect one end to battery negative and other end to the frame while the engine is running and then apply your brakes and read the DVOM…should be no more than 0.5 volts…do the same between battery negative and the engine block.
Last edited by C5 Diag; Nov 28, 2024 at 04:08 PM.
Thread Starter
Heel & Toe
Joined: Nov 2024
Posts: 17
Likes: 0
Well what you can try is if you have some jumper cables connect between the block and the frame and see if the lights still dim…if you have a DVOM connect one end to battery negative and other end to the frame while the engine is running and then apply your brakes and read the DVOM…should be no more than 0.5 volts…do the same between battery negative and the engine block.
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