I've got an 03 GMC Sierra 2500HD that has some AC issues. The heater will only kick in if the temperature is at max, 90. otherwise it actually blows cold air.
few things to note:
the ac blender works; it switches between all modes as needed. the actuator doors also work, had 2 that were bad and I replaced them.I verified that they all move as needed. I did the calibration several times to make sure that's not the issue. I flushed the heating cold that's under the dash also. Water pump works; got hot going in, warm coming out.
it has the digital AC control type; also I used 2 separate units to make sure i didn't have a bad one.. they both do the same thing.
fuses are good...
Any ideas?
Thank you in advance.
Dan
few things to note:
the ac blender works; it switches between all modes as needed. the actuator doors also work, had 2 that were bad and I replaced them.I verified that they all move as needed. I did the calibration several times to make sure that's not the issue. I flushed the heating cold that's under the dash also. Water pump works; got hot going in, warm coming out.
it has the digital AC control type; also I used 2 separate units to make sure i didn't have a bad one.. they both do the same thing.
fuses are good...
Any ideas?
Thank you in advance.
Dan