2004 Chevrolet Tahoe no heat or air in rear

2004 Tahoe with 107K, just purchased and after I get it home the kids tell me no heat in the rear controllers. Front seems to heat and cool fine but nothing I do gets any heat out of the rear. Went through the manual and everything seems ok. What am I missing or could it be?

This probably has a separate blower fan for the rear. Does that fan run? (You can sit in the car with the key on, everything else off, and just turn on some heat or air for the rear and listen).

If the blower fan isn’t running then you need to figure out why. Obviously you start with the fuse. Are you any good with a voltmeter?

Mine did not work on a blazer. We had spent a couple of years where heat and ac were fine in the front while driving, but stopping and slow traffic they were not, had to turn the fan up to 3, and that was too much change too fast. Fan speeds 1 and 2 are so quiet I did not realize they were not working. After I replaced the variable resistor, a really easy job the rear controls started working again also.

The fan does blow, but you can turn it to heat and it blows cold.

Thanks in advance

That’s kind of worse than if the blower didn’t work. First just check your coolant/antifreeze level. Then take it to a reputable, local mechanic for an evaluation. The heat is produced by the cooling system so you’ll want to get the cooling system a full once over. You may have something like a plugged heater core for the rear. It may also be an interior problem like with a control door in the duct work. But in general, a heat problem means a cooling system problem.