QuestionQUESTION: I heard a faster (double blink) when turning right and thought "Okay, I have a dead bulb." Located rear right blinker not working, removed and opened the assembly, and the bulb "looks" good. I change the bulb with a new, known working one, and still nothing. Looking closer, I noticed burn marks around the base where the bulb plugs in. This is a dual filament bulb, and the other (don't recall now, either break or running) light in the same socket works fine. Blinker still doesn't work with new bulb. Front blinker works (faster blink) and all other three hazard light blink - this right rear does not.
I'm thinking some kind of power surge that caused the burning around the base of the socket. Before I replace the socket (don't know how w/o buying an entire new assembly) I would like to know what would have caused the burn on this half of bulb in this one socket. And even if I replace the assembly, w/o knowing the cause it might happen again.
Any suggestions would be appreciated.
ANSWER: HI Mark,
I see this happen a lot especially on late 90's model chevy cars.
I just want to make sure i have the facts correct, your question was a little hard to follow. I think what you are saying is that the turn signal and running light are within the same bulb and that the turn signal filament doesn't light up but the running light does.
If this is the case, then here is what is going on.
When a Dual Filament bulb setup malfunctions this way, also when it creates a scorch mark on the housing assembly as you described, this is a problem with the signal sending wire. On the housing there are two or three wires, should be three that control the bulb, one for brake/turn, one for parking light, and one for ground. Using a test light or test meter that is designed for reading 12 Volt current, test each lead.
One should show ground
One should show power when the parking lights are on
The other should show power when the turn signal for that side is turned on, and also should show power when stepping on the brake pedal.
The wire that doesn't show power when turning on the turn signal and brake pedal is the problem, chances are it is either broken or has a bad connection, i think probably broken.
You will need to trace this wire backwards from the light to find where it is broken, it may be frayed or exposed at some point in the wire and possibly touching metal causing a ground fault or short to ground, which will create the scorching patterns you see and cause the light to stop working. Also check the fuse that controls that light to ensure it has not blown as a result of the short.
Check this first and let me know how you make out.
If this is not the solution we can go further into the diagnostic process.
Thank You
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QUESTION: Follow-up:
I removed the tail light, then tail light circuit board from the plug and thankfully all electrical signals checked okay to the plug. The problem was with the scorched socket. The contact had melted into socket and wasn't making contact with the bulb. I disassembled the tail light circuit board, removed the socket, and while attempting to gently remove the contact from the melted socket, it broke. The plastic clips on the socket were also scorched/brittle and first one broke off and then the other. I was able to make another contact lead out (flattened out a piece of copper wire, then grinded/filed it to size and bent it into shape, reassembled the circuit board, plugged back into the car, and the directional work, but the backup light wasn't working. After disassembling/reassembling the circuit board multiple times, with different lights working each time, I gave up and ordered a new tail light circuit board on line. I think the running lights (and maybe the break lights) work, but since the plastic clips that hold the bulb in broke off, even if all the lights worked I'd have to replace it to ensure vibrations don't cause the bulb to fall out.
I've found a wide range of prices for the tail light circuit board, but the best was around $14, with $7 shipping.
So after all this I'm confident that I will have fixed the light, but I'm not comfortable with the fact that I don't know what caused the problem in the first place, or know what I can do to prevent it in the future.
I checked all the fuses & cleaned the contacts on them and they all seemed fine. I'm suspicious of my mechanic, because this problem (and an oil leak) seemed to coincidentally manifest itself after I brought in the car to have a slow leak in one tire fixed (leaking around the rim) and a screw in the another tire removed/fixed. Is this type of problem random or could a definitive act have caused it? The mechanic was quick to remind me when I left that the car was due for inspection.
AnswerHi Mark,
Sorry for the delay in response i was away on personal business for the last two days. It sounds to me that from what you have described the problem lied in the circuit board, its very probable that the board wore out over time, this happens with chevrolet.
It is worth checking the wires going to the circuit board for proper signal and voltage, just to be certain that the problem does not lie in one of those wires.
I can not say for certain that your mechanic intentionally did something to cause this in the hopes that you would bring it back to him for repair,thus paying him to fix the problem. However, what i can tell you is that, if for any reason you are uncomfortable or suspicious of your mechanic,I would recommend looking for a new one. when it comes to vehicle repair, you need to be comfortable with and trust in your mechanic.
I recommend calling around and asking people you know to recommend a good reputable mechanic. Also you can check with the BBB (Better Business Bureau) to see if the mechanic you currently have has ever had claims filed against him for this type of behavior. ALL mechanics in all states are required to be licensed and each license is specific to each mechanic,so a call to your state licensing board could also give you information on whether or not he has had any claims filed against him as a mechanic rather then as a business.
The bottom line is that the problem you have experienced is not random, SOMETHING caused that circuit board to overload and malfunction, what it was exactly i can not say without visually inspecting the board and the vehicle, which i would be happy to do for you if you would like. you can find the contact information for my business here, www.hvemergency.com
If you need anything else please do not hesitate to ask.
Best of luck of your replacement, and if you need assistance with that please let me know and i will do my best to help guide you.
Thank You.
