I have an 07 grand prix that I bought used in 08. The blower quit working before the warranty ran out so I took it to the dealer. They said it needed a new "harness". Everything worked for a while then it happened again. This time I checked it out, the dealer hadnt put in a new harness but simply used a jumper wire to power the fan. We installed a new resistor at that time and the heater worked again. Fast forward a little while and it quit working again. This time we put a new head unit in it and it worked again for a while. This time it quit working and I put a new resistor in it. Didnt fix it, tried the old head unit, nothing. Checked the fuses in the engine bay and found a blorunwn main fuse, 30 amp. Bought a new fuse ($5), fixed it for about five minutes. At this time I had put the old resistor back in and it worked for five minutes then quit. I put the new resistor back in and let the car run for about 30 minutes with the fan on high. The next morning it quit working again, actually it never came on. The next thing to change is the ignition switch, but I dont know how to get it out. Any suggestions?