Electrical

[Big Mort]

I've been having a problem with the light in my 1980 corvette. The brake lights don't work, and the blinkers blink really slow. i dont know if these problems coincide with each other. there is power going through the fuse when the car is off and when its on. all the wires going around seem to be ok and intact.
would anyone know where to start and how to go about trouleshooting this problem. this is one of the last major things this car needs to be road worthy after a long time so any comments and pointers would be greatly appreciated!

mort

 

[petes74ttop]

Could it be this easy?

Hi and Happy Holidays.
For the brake lights, did you see if the switch at the brake pedal is making contact and working? Yes, you should have power to the brake lights when the key is off.
Have you tried a new flasher? PG.

 

[TimAT]

I'd go looking for the grounds to the taillights. A slow flash is indicitive of not enough load on the flasher. And with no brake lights, that also could be a ground problem- the bulbs use the same filament for both. Do the taillights work at all?

 

[FLATOUT427]

Check for corrosion on the turn signal cancelation switch. My '68 had almost identical problems and thats what I traced it to. Ed

 

[Yoda]

This may sound too simple... but first check to make sure the light bulbs are correct I believe they should be 1157 for the turn/brake and 1156 for the side markers and backup lights.

As mentioned above, check for loose or bad grounds and/or poor contact points on the socket and the bulbs.

Bud

 

[gmjunkie]

This may sound too simple... but first check to make sure the light bulbs are correct I believe they should be 1157 for the turn/brake and 1156 for the side markers and backup lights.

As mentioned above, check for loose or bad grounds and/or poor contact points on the socket and the bulbs.

Bud

I'm sure the side markers are 192's, Bud!! And he needs to check the Grounds!!!!!

 

[lone73]

I'd go looking for the grounds to the taillights. A slow flash is indicitive of not enough load on the flasher. And with no brake lights, that also could be a ground problem- the bulbs use the same filament for both. Do the taillights work at all?

Couldn't have said it better. I agree 100%. I would also start by buying a Haynes manual and taking a look at the electronics diagrams in the back. Or better yet, buy the FSM. Tracing electrical is like following a road to a destination. You start with a map (schematic).

good luck and let us know what you find please
.
.
.

 

[Mr. Chuck]

Brake Light Not Working

I've been having a problem with the light in my 1980 corvette. The brake lights don't work, and the blinkers blink really slow. i dont know if these problems coincide with each other. there is power going through the fuse when the car is off and when its on. all the wires going around seem to be ok and intact.
would anyone know where to start and how to go about trouleshooting this problem. this is one of the last major things this car needs to be road worthy after a long time so any comments and pointers would be greatly appreciated!

mort

Looking at my 81 shop manual the following may help, if the same as your 80 Vette, you can try the following:

If the panel instrument light are working & brightness varies with the panel adj'mt wheel, then you know the 20 amp fuse is good, which also powers the tail / brake lights / license plate light.

If your License Plate light is also out. It gets power through the Head Light switch, just like the Rear Markers, Tail light & Stop Light; Check the common Ground point "Under the left End of the Rear Cross Member".

If Lic Plate Light is working and is brightly lite, then I would suspect the lamps / /sockets at the other tail light locations. If none of the rear lamps are working, then suspect a bad connection at C124 (locate under the dash board forward of the head light switch), close to the under the dashboard floor light fixture or some other brake in the wiring aft of C124.

A marginal / poor connection at C124 can give you a voltage reading at the tail lamp sockets, but will fails to light the lamps. Using a test lamp to check from the center socket contact to frame ground, is better than a volt meter, since it loads the circuit and verifies the circuit will carry a load (light the respective lamps). Where as a volt meter can only detect an open circuit condition.
I.E., a test lamp tester is home made, a 12V lamp with one wire soldered to the center contact & another wire soldered to the metal base of the lamp (use of an old set of meter leads with probe on one wire & an alligator clip on the other end).
I hope this info doesn't go into much detail, but helps you locate you problem.

 

[6880 Mike]

...I'd go looking for the grounds to the taillights....

Bingo. First thing to check is the rear harness ground on the frame crossmember. These can crud up with road gook. Make sure you have a ground, clean ground.

 

[Mylo]

Same Problem

I have the exact same problem. This weekend I changed all of the lights,
at what point did tail lights get to be 2.50 each. :confused I noticed that there is a light under the car by the spare tire that would stay on?????? So I had to pull the bulb not to drain the battery. When I rev the engine the lights start to blink very slowly but if it at 500 rpm they will not. I was going to replace the relay but I will check the ground on the back also. Big Mort did you ever figure out what it was??

 

[herron]

Weird electrical things happening yesterday on my '81. No rear running lights, no brake lights, no turn indicators.

Checked all the fuses, they look fine. In fact, after cleaning the contacts and putting them back, I got my turn indicators ... but still no brake lights or running lights.

Changed all the bulbs on the rear of the car (one backup light was pretty corroded and the glass of the bulb broken) ... fixed all that ... got brake lights, turn indicators (chosen direction real strong with the other also flashing weakly), indicators stop when brakes applied. No backup lights.

Then I noticed the on-off light on the rear defroster toggle was flashing in time to the turn indicators! Also comes on when the brakes are applied. Turning the defrost switch on or off does not seem to do anything at all.

I'm thinking "short" somewhere ... but have no clue where to look?

Any ideas? ;help

 

[LVMYVT76]

I would check the grounds. Have you used a voltage meter to check for voltage at the light sockets??? Make sure you are going to a good ground when checking.

 

[Mr. Chuck]

Blinking Lights, Potential Cause

I have the exact same problem. This weekend I changed all of the lights,
at what point did tail lights get to be 2.50 each. :confused I noticed that there is a light under the car by the spare tire that would stay on?????? So I had to pull the bulb not to drain the battery. When I rev the engine the lights start to blink very slowly but if it at 500 rpm they will not. I was going to replace the relay but I will check the ground on the back also. Big Mort did you ever figure out what it was??

Had similar problem on my 80 Mavrick, found defective diodes in the alternator which converts AC voltage to DC. You can check by setting your volt meter to AC ~ 50 volt range; if you get a reading, it means that one or more diodes have failed. If you are a DIY person, replace the diode bridge inside the alternator with one from local auto parts house. You should also check the brushes length and replace if short / worn down.
Hope this is helpful.

 

[pdub67]

All Turn Signals Blink at Once!, But only in one direction...

This is my first post, so I'll try to make sense. I have a 92, LT1. When I turn the blinker to the right, all right lamps work except rear side lamp, however when I swicth to left side, all left side lights blink, and the right tail lights blink, but dimmer than the left. Now the right rear side lamp (which is a pain to change BTW) decides to work. I see previous post indicating a ground, but not exactly sure where to start.
I tried to remove one bulb at a time to see if I could isolate the problem, but had no luck.

Could it be the flasher solienoid itself?
I have the Haynes manual, but the electrical schematic is rather difficult to follow and I have an electrical background.

Any suggestions would be greatly appreciated.
Thanks,
Pat

 

[paz72vette]

This is my first post, so I'll try to make sense. I have a 92, LT1. When I turn the blinker to the right, all right lamps work except rear side lamp, however when I swicth to left side, all left side lights blink, and the right tail lights blink, but dimmer than the left. Now the right rear side lamp (which is a pain to change BTW) decides to work. I see previous post indicating a ground, but not exactly sure where to start.
I tried to remove one bulb at a time to see if I could isolate the problem, but had no luck.

Could it be the flasher solienoid itself?
I have the Haynes manual, but the electrical schematic is rather difficult to follow and I have an electrical background.

Any suggestions would be greatly appreciated.
Thanks,
Pat

Pat,

You have a better response in the C-4 section with a new thread.

Cheers

 

[frank_nesta]

It's a Corvette. Electrical problem. GROUNDs are the most likely problem. Rear lights. Check the ground at the rear corner of the frame driver's side. I hope this helps.