Brake Light Problem
Thread Starter
Navigator
Joined: Aug 2007
Posts: 9
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From: Atlanta GA
Brake Light Problem
My '70 has a strange brake light problem. The passenger side light works but the driver side does not. The socket is not getting any juice. I have a new Lectric Limited wiring harness. Does anybody have an idea where the break in the current could be?
Thread Starter
Navigator
Joined: Aug 2007
Posts: 9
Likes: 0
From: Atlanta GA
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
At the harmonica connection with the brake pedal pushed see if you have 12 volts to the dark green wire at "N".
Former Vendor
Joined: Aug 2006
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Here is a simplified schematic with some diagnostic suggestions.
Normally, when I go after a tail lamp problem I pull the connector off the brake lamp switch and make a jumper loop. This keeps the power flowing without having to keep pushing the brake pedal.
What makes no sense is that you have rear turn signals. It makes no sense because the only difference between the two is the source of the 12 volts. (One is direct from the pedal switch and the other from the flashed power source). So it kind of points more toward the switch than anywhere else.
I think I would do the following.
I would test for power at G with the turn signal in the off position. Then I would do the same test with the turn signal turned. If the turn signal works, then the wires from the switch to the tail lamp are good.
If you have power going in at E, and you don't have power coming out on O then I would take a hard look at the switch. When the turn signal blinks, is it as bright as the passenger side?
Willcox
Normally, when I go after a tail lamp problem I pull the connector off the brake lamp switch and make a jumper loop. This keeps the power flowing without having to keep pushing the brake pedal.
What makes no sense is that you have rear turn signals. It makes no sense because the only difference between the two is the source of the 12 volts. (One is direct from the pedal switch and the other from the flashed power source). So it kind of points more toward the switch than anywhere else.
I think I would do the following.
I would test for power at G with the turn signal in the off position. Then I would do the same test with the turn signal turned. If the turn signal works, then the wires from the switch to the tail lamp are good.
If you have power going in at E, and you don't have power coming out on O then I would take a hard look at the switch. When the turn signal blinks, is it as bright as the passenger side?
Willcox
Last edited by Willcox Corvette; Jul 9, 2014 at 10:52 PM.
Melting Slicks
Joined: Jun 2014
Posts: 2,226
Likes: 497
From: NJ
This may sound too simple but, try replacing the flasher. I tried tracing down an electrical problem similiar to yours for three days and found nothing, I practically opened the whole wire loom from front to back. Then, changed the turn signal flasher and Presto It worked . It might be worth a try in your case. Good Luck!
