I just got my car back from the dealership collision department Monday. They replaced the entire passenger side headlamp assembly and passenger side turn signal assembly along with some paint work.

I went for the first night drive Monday night. A mile or so up the road the dash lights and tail lights went out. I went home to discover the tail fuse had blown. I replaced it the next night and tried again. This time it blew almost immeditely. I went maybe a few feet. It may have blown when I pressed the pedal. I believe the ABS light was on just prior to this. I tried about three fuses. All of them kept blowing.

I called the dealership today and they asked me to try a new fuse on the way to work today without turning on my lights. I did this and the fuse did not blow. It seems this may only be happening when I turn on the lights at night. I'm assuming my brake lights are working ok in the day. I have not checked this yet. I'm going to flip through my FSM today. I'm unable to drive at night right now.

Any Ideas?

 

After some more driving it seems this only happens when I turn the switch on for either the daytime running(park) lights or headlights. The fuse blows right away. I checked the four rear brake lights and those are working fine.

 

i have the same problem, still aint figured it out yet. My tail lights work fine, but when I turn the lights on for night time driving, the fuse either goes out or goes out a couple of mins after turning them on. I need an answer for this one as well. (my car has been sitting for awhile though cause of vacuum leak, so i aint got around to fixing this one yet)

 

Not sayin it has anything to do with it but the tail fuse also powers the dash lights thru the headlight switch on my 85. Your problem may lie there somewhere.

 

I spent all yesterday evening and some of this morning trying to find the problem. I found that the brake lights and headlights are working fine. The tail light fuse is still blowing.

The tail light fuse is blowing at different times. Sometimes it blows immediately after turning on the parking or headlights whith the engine off. Sometimes it blows a few feet down the road while driving with the lights already on. Nothing is consistant. It's not allways blowing immediately when turning on the lights. Its not blowing from pressing on the break. It's not from shifting.

I noticed my 'check ABS' light comming on sometimes just before this happens. I thought I'd check the front two speed sensors and trans sensor. I ran over an office chair a month ago. The front wheel sensors looked ok. The only thing I found was that the trans sensor was covered in grease and had some trans fluid on the terminals. I cleaned it well with alcohol and a brush and plugged it back in. I thought maybe I found something but it is still blowing. Maybe the ABS error was unrelated or a seperate problem that I now resolved.

Although all four of my brake lights are working I noticed that the 5th rectangular light is out. I'm assuming that it is also supposed to light up? I think it's been off for a really long time. I can't remember the last time I saw it lit. I'll probably try to get it working today after work.

I need to isolate the problem. What I really need to know is what is on the circuit/fuse with the tail lights?? I belive the tail lights and parking lights are on that circuit but what else? Is the radio dimmer on that circuit? Is the 5th brake light on there? Cigarette Lighter? etc?

I've been reading through my FSM but still not getting anywhere. I'm not sure where to go from here. This evening I may pull all the brake lights and replace them, try to get the 5th brake light working, completely undo all my radio aftermarket radio connections, check both parking light harnesses, check brake light harnesses, etc.

Thanks

 

You clearly have a short circuit that is intermittent on the tail light circuit. If you have the electrical diagnosis GM manual for your car, you can find out all the circuits that are powered through the tail light fuse and trace the wires and see if you can see where the short is. Why don't you state what year Corvette you have? No one here is clairvoyant. All C4's are not wired exactly alike!
Another neat trick is to connect a 12v light bulb in place of the tail light fuse and start wiggling wires connected to this fuse. When a wire in this circuit shorts to ground, the light bulb lights up and passes a safe amount of current.

 

Year was stated is Sig on first post... 95-Lt1-auto-Polo-Conv. Thanks for the lightbulb trick I'll have to try that.

 

Always go back to what was touched last. At least that’s where I would start since the problem did not happen before the dealers work. I would give it a 200% visual and look-see real close at the wiring in the front of the car.

Do you think any other work was done in another area?

Did the dealer check out the lights before they gave you the car? And who's responsibility will it become to fix.

Can you also please state what fuse # you have been replacing. I assume it is #6. Looks like there are 7 lamps on that circuit. So do what JFB suggested and pull one lamp at a time as well as moving the wiring. Also, bulbs generally open when they go bad, but I have seen shorted bulbs, not many but it can happen.

Got other suggestions if the dealer does not repair it.

 

I'm going to look it all over again this evening really well and report back. No other work was done to the car other than the front bumper and headlights. They did have to splice some wires for the passenger headlight and motor. It's taped up pretty good. I didnt want to touch it until they can look at it so I don't get blamed for messing with it.

I don't believe the dealer looked at the rear lights before, not sure. I know that the tail fuse was not blowing like this before. It did maybe blow once several months ago. I'f it's something from hitting the chair or the front repair they did, they will have to fix it. Otherwise I'd rather save my money and fix it myself. The only reason I went to them is because I don't mess with body or paint work.

It is fuse number 6 that is blowing. The bulbs on it as far as I can tell are the 4 brake lights and the two front parking lights. What is the seventh?

I'll check the bulbs and wiring this evening. So how should I rig up this test light? Will any 12v bulb work?

Thanks again!

 

Check for a pinched wire

 

The seventh light is the license plate lamp.

At second thought I have a hard time relating the tail lights and the dash lights. They are completely different circuits. A lot of the dash is run by the CCM. The tail lights are a bunch of bulbs in parallel powered by 12 volts thru a switch, pretty basic. So for now I won't even address the dash.

Out of the gate I got to figure it's a dealer problem. Could be a coincidence, granted, anything could happen any time. But I'm targeting dealer

I would like to see what's under all that tape and how neat it was done.
It could be a pinched wire very possibly as said but the body is fiberglass which reduces that theory but does not eliminate it.

 

Sig shows up at home, but didn't at the crappy old computer at work.

 

I looked at the license lamp when I disconnected it to change the square brake light. It looked really dirty and I believe the bulb was cloudy. I havent noticed wether it was working or not. I'm assuming it comes on with the parking and tail lights. I'll have to hope I can get a new fuse to hold long enough to visually inspect it. Maybe at lunch I'll go pick up a bulb.

Yesterday evening I replaced the square brake light in the back. I thought I fixed the problem. I drove about two houses down the street and pop! I replaced the burnt fog light and got it working. I dont think that had anything to do with the problem anyway. I also completely pulled out the radio and made sure all stock radio wires were disconnected and all were wrapped. Still pop!

At this point I think I would have to agree. I think somewhere in the wiring the dealership messed with there is an issue. It's strange that the headlights are working fine though. Maybe its the parking lights. I did put a new fuse in and with the brake lights working I wiggled the wiring they taped up. The fuse did not blow. It only blew when I went down the street a few feet.

The other night after all the different tests I was doing I was wondering if it had something to do with a motion or tilt sensor or my viper alarm. The tail fuse blew imediately when the back was elevated on the slant in my drive way but it didnt immediately blow when I was pulled in forward or level. It did blow when rolling a few feet up the street. Then I was thinking maybe it was one of the speed sensors. As you can tell this is driving my ****ing nutz! I'm going back to the dealer today at lunch to see what help they can offer.

This is my only car and daily driver and since I live alone I am stuck at home at night unable to drive anywhere. I am in the process of looking for a used truck to buy as a backup plan. I think I may have found one.

Thanks again!




Ignor the writting and red arrows. This was a pic for a rubbing issue they had before I got it back. Here you can see the wires they taped up on the right side of the headlight. This is supposedly the only wrire they had to splice.

 

Looks like I am having to eat some crow on this one on some things I said but will turn out to be quite learning experience. Wanted to give this problem some additional effort because too many things did not feel right, so. I wanted to see what the effect would be if I pulled fuse #6. I expected the tail lights to go out but had very unexpected results.

Not only did my tail lights and rear side lights go out, but so did all four lights front and side. The dash lights were out also and the chime did not work with light switch on and door open. Wow, the dash speedometer and warning lights were OK, but the night time illumination lights did not work. So NOW I see what you mean.

Wanted to post results soon as possible and had not had time to try to come up with a solid answer as to here is what is happening technically. That may take a while as the FSM does not lead you to any normal reason as to why all these circuits are related in such a way.

But the one initial logical conclusion I see so far is that if you short out ANY of the running lights, the tail light fuse will blow. So if the front running lights in front are messed up, that would affect all I have mentioned in simulated test.

Dammmmm…….

 

OK so now I see what is happening, did not take as long as I thought once I was looking for it.
Page 8A-110-4, wire s217 goes over to page 8A-12-3 connecting with wire s217. It's obvious now that it feeds all the lights as well as the CCM. That answers the chime and dash lights as that is a required input to the CCM for light switch on which in turn turns on the dash lights and chimes.

So the tail light fuse #6 feeds much more than just the rear of the car. I think the labeling of the fuse should have been different.

Should have picked that up last light but just did not look far enough until I did my test today and saw what was really happening.

Dealer, Dealer, Dealer, Dealer………………

Those wires have to be connected incorrectly somehow.

 

I agree the fuse doesnt make sense. I went to the dealer today at lunch. One of the guys came out and we tried all kinds of different things so he could see what it was doing and when it was blowing. He was going to relay the info to his tech. If I can't solve it this weekend it's going back to the shop next week.

Something new happened when I got it home today. I turned the parking lights on in my driveway then walked around it shaking wires again to see if I could locate the problem. I shook some wires in the pic above and the fuse blew. Was it a coinsidence and it just happened to blow at that time. hmm.. Maybe not. Now it is blowing every time, immediately after turning the switch. So maybe I shook something loose in the wires. In the morning I am going to undo those wires and reconnect them and try a new fuse. I sure hope I found it.

 

OK so this morning I was able to get out the drive way again and a few feet down the street before it blew.

Question... I pierced the two wires behind my turn signal light socket without the bulb in place and I am getting continuity(.00 ohms) on my Multimeter. Should I be getting continuity here?

Bad Socket?

 

A true reading of 00.0000 would be bad if it was a dead short & if you carried the decimal out a few places. It depends on what your meter can read past the decimal. But the fact is if all was working correctly, you would be measuring across all running lights that are in parallel. Looks like there might be about 11 lamps you are measuring across and that resistance has to be real low. I don’t know what the resistance value might be and won't give a solid answer, but I will venture a loose guess that it could be one or two ohms or perhaps lower than 1 ohm. And don’t forget this is the cold resistance of the filaments.

You really need a solid connection with the meter leads and then move the wires and see if there is a change in the meter reading. What is really going to happen in the end is the taped up section needs to be un-taped and a inspection needs to be performed for proper connections. Probably by the time the whole mess is un-taped the problem might clear. If that happens, then it just needs to be taped up properly with a little more care.

 

I sorta eliminned the taped wiring from the picture above. The other day when it blew both motor/headlight harnesses were completely disconnected. It was still blowing the fuse with the area they taped out of the picture. They were supposed to call me this morning to tell me the correct way to test that turn signal socket before I cut one of the wires. I havent heard from them yet. I'm going to head back over to the dealer at lunch.

 

Late to the party, I know. I would advise checking all sockets on that circuit for shorts or corrosion - even if they weren't affected by the collision. My wife backed her Dodge into a post which took out the rear tail lamp assembly. The fuse for that circuit kept blowing also even after replacing the tail lamp - finally traced the problem to a front parking lamp socket that was badly corroded. I'm guessing the initial impact loosened some corrosion in the socket which shorted the circuit out.