Brrrrrrr N-n-n-n-no h-h-h-h-h-heat

[George Selby]

Those are my teeth chattering in the subject line.

My 89 80 4 cyl occasionally has heat coming out the defroster vent, rarely 
has heat coming out the dash vent, and never has heat coming out of the 
floor vent.  Even if, for instance, heat was in fact coming out the 
defroster vent, if I turn the air output selector knob to floor output no 
heat comes out, although the air starts blowing out of the appropriate 
location.  I find this very peculiar.  The heat output does not vary with 
engine temp, unless engine is stone cold, in which case there is never 
heat, but the needle can move from below center to above center and the 
output doesn't change.

I took off the heater hoses from the engine, and ran water from a hose 
through the heater core, seems to have no restriction to flow.  I made sure 
the system was full by removing the coolant temp sensor while the car was 
running cold, then let it heat up, some air came out, but the heat doesn't 
work any better.

George Selby