Had problems with mine, fortunately it was still under warranty.
try the bend door
Many of these controls are Vacuum operated. You may have a problem where the "Main" Vacuum line has broken. See if you can locate this line by using your manual and make sure that it is intact. TommyTrouble
Mercury Mountaineers have a "blend" door in the heater box. It is probably malfunctioning. You can find more info by searching for Ford + "blend door" or "no Heat"
There is also a electic control moter on top of your hear inside your cab controls your heat check and see if that is working ,that is what i found out that was wrong with mine
There isn't a fuse for the engine block heater , it is like the heating element in an electric kettle , as long as it is plugged in and you are not using a timer or some other device that controls the electricity , then the block heater is on ( assuming that there isn't a break in the block heater cord , which has happened to me a couple of times , where I've had to put a new " male " end on the block heater cord ) or something wrong with the heating element
The air mix door on the in cab part of the unit is stuck in the heat position. follow the cables down from the controls on the dash and you will find the lever that controls the mix door, flip it the other way. for repair you will need to disassemble the heater unit if the cable has not just come loose from the arm.
Check your vacucum lines. My brother has the same problem. That's what we found was wrong.
There Ain't Nothin' Wrong with the Radio was created on 1992-02-10.
When my heater didn't work i had to replace my thermostat.
Whats wrong with it?
When I turn the car on to Accessory the radio works but everything else just stays dead.
We need to know what is wrong with the heater before it can be fixed.