I have the auto HVAC in my 03 Silverado and now for it to go hot it has to be at 90 (all the way up). Anything less than 90 is full cold. Is there a temp sensor that has gone bad or is it the control unit/ECM? Any input is welcome.

 

Truck is pissed at you for buying the new one.

Full cold, like the A/C is on?? Or just outside air temp? I think there's a re-synch procedure for the temp door actuator, but I've seen alot of them that it didn't work on & had to have the actuator replaced. But if the A/C is coming on, I just don't know off the top of my head.

 

Well it's hard to say, I took the A/C belt off in the tundra last summer and never hooked it back up so I don't know if it's full cold or not. Just seems odd that it will switch back and forth but only at 90*.

Seems like a temp sender but the diagrams I have don't list one...

 

Lemme try to find the re-synch procedure. BRB