1995 F250 7.3L

i've got the heater turned up to the max (control wire is hooked up correctly)

lines in and out of core are hot (as is the core)

i only get warm air from vent position, and cool air from defrost and floor.

any ideas?

 

How hot are the heater hoses? Should be hot enough that you can't hang onto them very long.

 

i think most people wouldn't want to hang on to them for long. and the heat seems even between the two.

all the searching i've done makes me think it might be the "pen down the defroster" problem. i think i'll be diving into that today (any hints on making that as easy as possible?)

any other ideas jim?

 

Yep, those heater hoses should be as hot as the engine coolant, pretty darn hot. I had to ask just incase you were having a cooling problem.

It seems to be a blend door issue. These are not known to be a problem like the new model trucks. I haven't had one apart but it's not easy to get to either. A pen down the defrost duct may be on track. Let us know how it goes for you, it may help others in the future.

 

well, the smoking gun turns out to be... a pen. it was blocking the door from going to the full heat position. once i took the heater core out, i was able to reach in deep enough to feel/grab it.

all is well.