ok i have 1993 z28 camaro. i am cluesless about my heat. i havd the thermastat change, heater core change, flush the heater lines. the car still blow luke warm air. also before i had the all those things replace the upper air vents work now they dont they only blow at the lower level even if i have place the control for the upper level. what else could it be i dont understand it is getting cold. what else could it be.

 

Make sure the temp control is working properly. The cable from the control to the air door has to be set properly so that the air door can open and close fully. If not, the air getsrouted around the heater core and doesn't get hot.

 

i don't know if you tried this but my car has the same thing wrong and i was told to replace the anitfreeze and the coil. mabey its also a fuse? idk dude but in Indiana with this cold weather, i freeze in my car (tommorow its supposed to hit like 10 degrees)