Taillight Problem GMC Sierra?

[ramyjr02]

Why is it that on my 2000 GMC Sierra my taillights are always on like normal but when i hit the brake the right one turns off but i let go of the brake and turns back on like normal. what is the problem ???

Thanks !!

 

[redhzkingswood]

The problem is a most likely short somewhere in the wiring caused by rust, or possibly one of the globes has been put in the wrong way. If it is one of those combined stop/taillights then maybe the globe has been put in wrong despite the fact it has offset pins to make sure it goes in correctly.
This is a common Ford and GM problem, the light units let in moisture and rust forms causing a short circuit.

 

[Fermin M]

check the tail lamp bulb, some bulb are dual and have two wire inside, if one brakes the other one still works. that could cause the light to turn off when you press the brakes.

 

[Michael]

You definitely have a short. To fix it you'll need a voltmeter to track down the wire if a visual check doesn't find it.