Burn in the brake light circuit, solder?

[aerius007]

My drivers side break light is out. I was changing the bulb and noticed a burn in the circuit board. Is this the sign of a short that could possibly still be present or is it a fairly common thing that happens. I plan on soldering the burn to fill in the pit and replacing the bulb. Bad idea?

You can see the burn hole in this picture, it is at exactly 9 o'clock next to the bulb socket.

http://i478.photobucket.com/albums/rr146/aerius007/BMW750il/8abf6df9.jpg

Thanks for helping me along with this project.

[Jaaap]

A burn hole through metal?
If you say it's a hole (as opposed to some molten plastic on top of it) i believe you but just leave it open, why solder it?

If the light works as intended, leave it as is.

[novasol]

Looks like a wear hole to me. I had a similar thing last year and put a piece of tinfoil over and under it so the socket would make good contact. It's been working ever since.

[aerius007]

A burn hole through metal?
If you say it's a hole (as opposed to some molten plastic on top of it) i believe you but just leave it open, why solder it?

If the light works as intended, leave it as is.

It needs to be soldered because it is where the contacts for the bulb are. Can't complete a circuit if the contacts are touching plastic.

[IcemanBHE]

It needs to be soldered because it is where the contacts for the bulb are. Can't complete a circuit if the contacts are touching plastic.

You have your answer...

[aerius007]

You have your answer...

Ok, I'll get to soldering and hope for the best. My main concern was that I would fry through something else and cause more damage (something caused a meltdown once) if there some other issue that needs addressed.

[Edwin NL]

Soldering won't cause a short, if you want to be safe just pull the connector from the taillight while your working there

[aerius007]

Soldering won't cause a short, if you want to be safe just pull the connector from the taillight while your working there

Yeah, I wasn't worried about creating a short though. I was worried that there is a short in the line that caused the original hole to burn. If I solder the burn hole, and there is a short in the system, I'll only burn another hole and cause more damage (melt wire, fry light control modules, etc). For some reason just soldering the hole seems the same to me as blowing a fuse and just replacing it with a bigger one.

Analagy: Somebody gets shot in the stomach, the doctor doesn't remove the bullet and just puts a band aid on it. The doctor didn't solve the actual problem (bullet still in the belly).

My car might have a problem which caused the original burn. All I'm doing is putting a band aid on it, not fixing what caused the problem. I doubt it's normal to randomly burn a hole in the circuit. Regardless, I soldered the lights and we will see.

[IcemanBHE]

Its more likley that a PO tried the wrong bulb there and pulled too much juice.

Make sure the fuse is the right size...solder it an watch for a few days. The fuse will protect the circuit.

[aerius007]

Its more likley that a PO tried the wrong bulb there and pulled too much juice.

Make sure the fuse is the right size...solder it an watch for a few days. The fuse will protect the circuit.

Great, thanks Ice. I soldered the board last night, installed today and for the brief time the car was running I didn't have any problems or faults. :)

[Pedro Rabie]

Those holes are caused by poor contact -> that causes resistance's increase-> that causes heat-> that causes accelerated corrosion.

You can fill the hole with solder but be carefull sanding the metal surface to make it solder friendly and then sanding the filling to leave it to the same level of the surrounding metal. Also sand the part that was in touch with the hole because it should be affected too. A 400 grain sand paper is ok for the job.

Tip1: Unplug the battery
Tip2: 30W soldering iron is ok for tis job.
Tip3: Once you have this in one bulb, there are good chances of suffer the same problem in others. Lightly sand them all.

Regards

Pedro

[aerius007]

Pedro,

Thanks much for the explanation!

[Pedro Rabie]

Tip 4: To fill a vertical hole with melted solder is a task for trained pros. I strongly recommend you to take the tail light out and perform the task in horizontal position. Otherwise you'll be risking to have small drops of melted solder in the most odd places.

Pedro

Pedro