We have a '96 Explorer staff vehicle on the fire department......it wont switch to heat....would that be because of a bad blend door actuator?

 

If hot coolant is flowing through the heater core like it's supposed to, then it's probably a blend door and/or BDA issue. Make sure that the heater control valve is not sticking shut.

Is it electronic (EATC) or manual?

 

it is the manual controls.............

i will check the heater control valve, but i believe it is working fine....

 

Now is the problem that it will only let air come out the top, Either vents or defroster, or is it that the air coming out is cool. If it is the former I believe that when the system fails it defaults to Defrost. If it is the latter, I don't know? Maybe a broken cable?

~HJ

 

it only comes out cold......the selector switch works (which is what the vacuum lines operate)