Trying to help a friend. Heat stopped working the other day.
New thermostat. Radiator hoses and heater core inlet AND outlet hoses get nice and toasty. No core leaks or coolant noticed under dash or on the floor. Seems to blow AC no matter where temp is set (65' - 85") Ambient temp was 62'. Pulled radio/AC/heat assembly from dash to look around inside. Can see vent control moving/rotating for dash, defrost, floor outlets.
Any ideas or suggestions?
Saw a Dec/04 post about heat/ac self diagnosis and will try that.

Usually it is air mixer the door that breaks from non-use and sticking closed.

Bingo. Thanks.
The neighbor just stopped by to tell me about the broken door.
Winter is near so he's just going to prop it open with something for now.

Are there seperate systems/doors for the heat and the AC?
The AC seemed to be changing directions when we were first trying to figure out the problem.

Are there seperate systems/doors for the heat and the AC?
The AC seemed to be changing directions when we were first trying to figure out the problem.
The air mix door regulates the hot air and AC mix. There are other doors for directing the air to various vents.

Might check at NICOclub for an article of someone who repaired his door without taking the dash completety apart.