brake problem

The only way to turn on the 2005 Tahoe is by remote access and placing the key in. Everything is fine when it turns on. The moment I press the brake to put it in drive, the brake light on the instrument panel turns on, 4wd goes to the lowest gear, and the air conditioning turns off. Already...

Ok so I bought a 2004 Z71 Tahoe the other day and it has a lot of issues that I can't figure out! 1. When you turn the key on and try to start it, it won't start. It does click or anything when trying to turn it I've. Also all the lights on the instrument panel go out. The security light is...