Thanks for the reply. I also had one in a buick but not a truck. This guy was driving and his butt kept getting hotter & hotter and then he saw a puff of dark smoke come from under the drivers seat on the right side, stopped, jumped out and saw his drivers seat comsumed by fire. He started his truck that morning, let it run 15 to 20 minutes with the heater on and the heated seat switch (in drivers door) turned on. He said he went to a bank and got out, made his deposit, got back into the truck and drove away not turning his seat back on. He says the seat will switch off when you take the key out. The cab is gutted but the electronics in the drivers seat are still in tact. I'm waiting for a GM guy to do a further inspection. Just looking for some ideas. Thanks again.