Problem with aftermarket LED 3rd brake light
 

My buddy just ordered an LED third brake light for his 96 ex cab Obs z71, He also ordered LED taillights to match and they work fine, but with the third brake light hooked up its staying on all the time, Its not the brake light just the tail light. The only time it turns off is when the door is open and the interior light is on. He didn't have this problem with the stock third brake light. Does anybody have any suggestions??

Thanks.

Re: Problem with aftermarket LED 3rd brake light
 

Wires are mixed up somewhere. Does it also have cargo lights? I suspect that the ground and power wires somehow are mixed up. If it was a plug and play replacement item it could be they screwed up the harness while assembling it.

Re: Problem with aftermarket LED 3rd brake light
 

The cargo light is messed up in the truck so we can't test if they work on the third brake light or not so there might be a problem with the wiring in the dash. We put a test light on the harness that the brake light plugs in and one of the prongs is hot all the time so that tells me it's in the truck and not the light, but the stock light didn't do that.

Re: Problem with aftermarket LED 3rd brake light
 

It could be that the voltage while not enough to light up the incandescent bulb is more than enough to light up the led's. Also I guess really I should say wattage or current cause the voltage probably has little to do with it.

Either way sounds like you have something shorted probably to ground somewhere as if I remember correctly you may always have a hot lead but not always the ground.

Re: Problem with aftermarket LED 3rd brake light
 

He found out that a prong on the cargo lamp switch was bent and making contact with another prong and causing the fuse to blow when he turned on the cargo lamp, he fixed that but the third light is still stuck on, and I agree about the power difference with the LED's, they require less power than the stock bulbs. I had an Idea to tape up the prong that stays hot all the time on the light and see if the brake light still works, if so just cut it so it wont stay on all the time and still have the brake light useable.

Did you ever figure this out? I just had the same Thing happen on my 97 gmc. Put an led third brake light in and it stays on until I open the door. The stock light works fine. The cargo lamps turn on and off like they should when I use the switch. Is there a short somewhere? I use my volt meter and the one white wire stays hot all the time. Not sure if it’s supposed to or not?
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Re: Problem with aftermarket LED 3rd brake light
 

cut the yellow wire if it has one on it

Re: Problem with aftermarket LED 3rd brake light
 

5 year old thread....