[dcarrb]

Setting AUTO, thermostat @ 85, AC compressor and radiator cooling fans run and "conditioned" air comes out the floor registers. Not one calorie of heat from anywhere, regardless of setting. Failure was abrupt and complete.

Coolant level and temp normal, both inlet and outlet heater hoses hot, so it's not coolant/heater core related.

I observed proper operation of that "mix door engine" on my other car; the question is, is that unit shot, or is it inoperative for some other reason? The bit about the AC compressor running with the thermostat on 85 seems odd if the problem is noting but an air-mis door.

It occurred to me to swap 'em but I'm too old and fat and farsighted to relish fiddling with something up under the dashboard of my car until absolutely necessary. Thought I'd seek counsel here first. I appreciate the input.

dcb