Relay? 2002 Trailblazer!
 

In the process of replacing the water pump, we fried something. My stereo, interior lights, heater/AC, windows, backup lights, and power locks won't work. It also won't shift itself. But it isn't giving me any codes or info! The digital part of my dash display works, but I'm not getting any info except the usual. We replaced a relay but nothing has changed. HELP!!!! I can't afford to take it to the dealer!