I bough an 02 Mountaineer last fall and I noticed that i could not adjust the temp. The heat always blew really hot. Well spring is here now and so I replaced the heater control unit in the dash thinking that the dial was bad for adjusting the temp. That did not fix the problem. Any suggestions on what might be the problem?

 

if it's the manual system, the cable to the baffle between the heater and AC coils is probably broken or not connected. If it's the automatic system... there's half a dozen things to check (vacuum lines, solenoids, etc).

Let us know whether it's the manual one or the automatic one.

 

The temp blend door has an electric actuator on the manual and automatic system.. Could be the actuator itself, or the blend door could be jammed/broken (This was a problem on earlier models, dunno about '02)

The manual contol has only one actuator.. It's up under the dash on the driver side bolted to the heater box...

The Automatic temp control should also be dual zone (pass and driver temp control) I woudl find it odd for both of them not to be working..

 

Thanks everyone. i will check those things and let you know what I find. I appreciate the input.

 

I figured out the issue. The vacuum line is not sucking to open the valve in the line. I traced the vacuum hose back into behind the dash but it goes back in to no mans land. Are there any hose diagrams floating around out there? Or any instructions for getting at the area behind where the radio and heater controls are at?