2000 Gmc Sierra Quirky Brake Light Problem

[Bill2000sierra]

Hi guys. Just want to say thanks in advance for any input you can give. I'm pulling my hair out. I have a 2000 Sierra SLE z71 that is giving me fits. Here's what I know so far. When I start the truck, the tail lights come on, even during the day. When I press the brake, the tail lights go out, but the center brake light works normal. Also, if I turn on either turn signal, they work until I press the brake pedal. I've checked fuses, wiring and grounds and haven't noticed any problems with these items.

[gmtech4]

it sounds not good ,and the internet is NOT the place for you ,have a guy that can read a schmatic go thru it ,sry my 2 cents

[Bill2000sierra]

ok, I just wanted to let everyone know what was wrong with my truck. It turned out to be the bussing block for the rear lights. It was shorting out, causing the lights to do all sorts of crazy things. Replaced the bussing block and all is fixed.