Heat only works on one setting

[JeremyCampbell]

I have a 2001 F-150 .When I try to adjust the blower switch for heat or fan,it only works on the high setting.Should I look for a fuse that's bad or take it all apart to replace the switch?

[highlife4me]

More than likely you have a bad blower motor resistor. The resistor is located behind the glove box and is fairly easy to replace. There probably are some videos on the net showing you how to do this. Good luck.

[CAMAN]

Yup, sounds like the resistor. When you replace it be sure to clean the contacts thoroughly to clean metal with a small file or emery board and place a liberal amount of dielectric grease on the contacts. Otherwise you will be replacing it again sometime soon.

[Jeremy airjer W]

Blower resistor would be my first suspect.