Brake light question

[ghostvbhc]

I'm still having a few problems with my brake lights, I replaced the brake light switch and we checked the grounds in one of the brake lights to see if my grounds were the problem and that didn't work. We really thought replacing the brake light switch would have worked, but nope. Whenever I turn on my lights in the truck, everything else works but the brake lights. Anymore advice on this? We're thinking of just taking it to an electrical shop and having the entire electrical system replaced and checked because the guy we got the truck from butchered the hell out of the wiring.
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[truckster]

Please clarify - are you saying the brake lights work when the headlight switch is off, or they don't work at all?

[ghostvbhc]

When the headlight switch is turned on, they both don't work. When it's turned off, they work. That's what was happening the last time we checked them. Ill check them again tonight and see to be completely sure.
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[piecesparts]

This still sounds like a grounding issue.

[ghostvbhc]

That's what we checked, but honestly we aren't electricians haha. How would we go about checking the ground wires for the brake lights and if so how would we fix them? Any pictures could help me a bunch too.
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[67Slider]

I had an issue with one of my brake lights not working. Not when I had the headlights on tho. Ended up needing a new turn signal switch in the steering column. For what its worth.

[ghostvbhc]

Originally Posted by 67Slider

I had an issue with one of my brake lights not working. Not when I had the headlights on tho. Ended up needing a new turn signal switch in the steering column. For what its worth.

As of right now, the turn signal thing right next to the steering wheel broke off and that might very well be the issue.

Originally Posted by GMCJOE

There is a lot of possibilities. A bad light switch could cause the issue. Might try replacing it to see if that is cause the issue. But I would definitely pull all the grounds for the lights and clean both surfaces, put them back and see if your issue is solved. Doing this first doesn't cost you money. Replacing parts does. The reason I say it could be your light switch is because you say the issue is happening only when you turn them on.

Do the tail lights work with the lights on? Do the turn signals still work with them on? Does either work with the lights on and brake pedal depressed?

Let me check them right now and I'll get back to on it.

Originally Posted by pat 70/71

maybe try grounding the housing with a new ground wire to the frame. I had a similar issue with my stepper and found it worked for me (too much crud under the fenders in my case) cheers, Pat

I might have to do that this weekend.

[GMCJOE]

There is a lot of possibilities. A bad light switch could cause the issue. Might try replacing it to see if that is cause the issue. But I would definitely pull all the grounds for the lights and clean both surfaces, put them back and see if your issue is solved. Doing this first doesn't cost you money. Replacing parts does. The reason I say it could be your light switch is because you say the issue is happening only when you turn them on.

Do the tail lights work with the lights on? Do the turn signals still work with them on? Does either work with the lights on and brake pedal depressed?

[pat 70/71]

maybe try grounding the housing with a new ground wire to the frame. I had a similar issue with my stepper and found it worked for me (too much crud under the fenders in my case) cheers, Pat

[ghostvbhc]

So, I went to check and as of right now, when the trucks completely off the brake lights don't work at all. When I turn the truck on (not start it since my fuel filter isn't hooked up at the moment) only the left tail light works and the brake lights don't light up when I step on the breaks and the right tail light and brake light aren't coming on at all even with the lights turned on.

[GMCJOE]

I would go with grounds right now, cause that what it sounds like. Work your way to replacing parts. How long has this been going on since you have had the truck?

Though, I would say if you had an extra light switch to try it before going thru all the grounds. A bad light switch was causing some funky issue with mine, I just happened to have an extra one that came with the truck as parts. I got lucky and didn't have to chase wires. Let me tell you, there is some funny stuff they did under the dash. Clean, but funky. None of my lights work till I turn the ignition on. So, good luck if you have to deal with something like I have going. I picked up a wiring harness out of a 71 recently for $75. Nothing chopped up. So, if you have to resort to a dash wiring harness I hope you have the same luck.

[ghostvbhc]

We already replaced the under the dash wiring harness, we found a guy that lived extremely close to us and we scooped it up as fast as possible when we found out he only wanted $60 for it. Nothing chopped up, it was still in the original box too. Anyways, we replaced it, but the brake lights and tail lights were working with the old wiring harness, but he had it chopped up extremely bad under the dash and where the tail lights hook up also. He destroyed most of the wiring in this truck. We tried checking the grounds on the right one and my dad had put a new ground wire and put it on a clean surface, but now it doesn't work at all haha. We're gonna have to go through the grounds again and possibly check that light switch this weekend too. Which light switch are you talking about? I replaced the brake light switch, the one that goes right above the brake pedal (I'm sure you know that though haha).

[GMCJOE]

I am talking about the actual light switch. So, it hasn't worked right since you put the new harness in?

[ghostvbhc]

Just to clarify, I have a 69 c10. But, you're talking about the one I would pull out to turn the lights on, correct? If that's it, yes the brake lights and the tail lights are the only things that aren't working when we replaced the wiring harness. Well, the left tail light works (the brake lights don't work on either of them and the right tail light doesn't come on either).

[GMCJOE]

Yes, the pull out one. You could have messed it up pulling the connector off the back of it.

I will see about finding you a wiring diagram. Check to make sure you have everything hooked up right, including grounds.

[GMCJOE]

This is a thread with wiring diagram. May be helpful.

http://67-72chevytrucks.com/vboard/s...d.php?t=185856

[ghostvbhc]

We've already looked over that one when we replaced the wiring harness, but we're gonna have to go over it again and see what's going on and if we did something wrong. I'll update you when we look at it this weekend.

[VetteVet]

Here's a link to a few diagrams, the ones you need are on top of the list. Click on the magnifier and they zoom up big.
...........http://www.2heeldrive.com/Chevrolet/Wiring_Diagrams/

Does your dome light work?

[bonnieclyde100]

as far as grounds are concerned you might check your ground straps that ground the bed to the chassis because if the body is not grounded good the lights wont be grounded good.

[ghostvbhc]

Originally Posted by VetteVet

Here's a link to a few diagrams, the ones you need are on top of the list. Click on the magnifier and they zoom up big.
...........http://www.2heeldrive.com/Chevrolet/Wiring_Diagrams/

Does your dome light work?

We're gonna have to look over the diagrams and see what's going on. We just can never figure out because the guy that had the truck butchered the wiring, like putting a bunch of wires that aren't suppose to be there and splicing a bunch of stuff together everywhere. We still have to check the dome light, I'm sure we haven't gotten around to hooking it up and getting the bulbs for it since we've been focusing more on the power steering. But, like I said we're gonna check all of this stuff out this weekend when me an my dad have time.
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[VetteVet]

Your head light switch powers the tail lights and parking lights but the power for your brake and turn signal lights comes from the fuse panel and the orange wire in the diagram is the feed wire to the brake switch for the brake lights. It also powers the dome light which was the reason for my question.
The way you describe your wiring harness makes it very hard to diagnose the problem, however I do agree that you have a serious grounding problem.

[ghostvbhc]

Yeah, the way the guy before us had his wiring was extremely bad and weird. He spliced a bunch of wires going to things that we can't figure out that the hell they went to or why they were there. I'll update you guys and see if we can figure anything out this weekend.

[ghostvbhc]

Okay well quick update for you guys, I checked some of the ground wires and played around with them and I have the brake lights working when the lights are turned off, but when I turn the lights on the tail lights also work but the left brake light works and the right one doesn't....
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[VetteVet]

Check the bulb to socket ground and the socket to ground. I believe there is too much resistance to ground when the tail lights are on for the brake light to work. You might need a new bulb also.

[ghostvbhc]

Ill be doing that tomorrow and ill again update you when I do it. Hopefully, that solves the problem.
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