My '01 Tahoe was fine. Both front and rear a.c. and heat worked perfectly. Then one day the front just stopped blowing. Rear worked fine, though I don't know if it blew COLD air. Then after a week or So, the rear stopped working. Changed the control panel, nada. Put original panel back in just now, and front still didn't work, but the rear came on full blast (only natural temp, no cold air) and it wouldn't shut off at all until I took the key out. Do I need to replace a fuse? Blower motor? Resistor?? Please help - it's getting so hot!

 

if it works "sort of" with the old panel and not at all with the new panel, I would suspect a problem with the replacement panel