The blower works fine but the heat in the rear just stopped working. Its 20° out today and need to get it fixed ASAP. Thanks for any help.
Most likely the blend door which is by the fan. To check to see if the heater core is working feel the inlet and outlet hoses. I think your truck has a 2nd one behind the controls
if you pull the rear passenger panel off then you can see the blower and 2 door actuators, the rear actuator closest to the blower motor is the one that controls hot cold the one closer to the front controls up/down. on my nbs the dealer wanted $127 fleet price, if you can wait and order it online you can get it cheaper. sometimes the aftermarket ones are darn near the same price locally.
If the actuators are fine then its most likely the HVAC control module which is very common.Mine went out 2 weeks ago-watched a you tube video and easy fix.
