Cannot regulate heat on any setting

[DCOWENS1]

Hi my sons 1997 Explorer is blowing heat at any setting on the temp control and he can only get AC at the MAX setting. Does anyone have any ideas on how to correct this?
Thanks,
David

 

[my98nnj]

Typical blend door issue. There is a post in the sticks or just google ford explorer blend door.

 

[koda2000]

if the problem is always hot it might be your heater control valve is stuck open. it lives under the hood on the passenger side, works on vaccum and allows hot water from the engine to enter the cabin/heater core. they can stick, lose vaccum or leak water. check to see if both the heater hoses connected to the valve are hot. with heater temp off, only one should be hot to the touch, the other not so much.

 

[masospaghetti]

I would second the blend door issue, although I can't explain why the MAX setting would work (I know the air is recirculated, but it seems like it would still pass through the blend door area). I have the same problem with mine, apparently its very common on 95-98 explorers.

 

[SoNic67]

Probably the blend door got stuck in an intermediate position. On MAX A/C the outside water valve is shutoff (and only on that setting) so maybe he can feel the A/C, but it does not mean that is working as it should.

PS: Mine was blasting hot air all the time - I drove all summer with the water valve in the engine compartment closed manually in order to have A/C. In fall, I needed the defrost so I did replace finally the actuator.