Heater/AC only works on High, no low/med.

[Metallic36]

So now, my heater/AC controls only work when it's on "4". 1, 2, and 3 doesn't do anything, and there is not a difference in any of those. Just wondering what may be the cause of this and how to fix it.

 

[mp3-79bronco]

theres a 'how to' on this but its usually only the 2-3 that go out

 

[MSP-BCH]

Take the surround out and if u have an air compressor blow out all the dust and if u have electrical contact cleaner then spray it down with that and also finish blowing off with compressed air....GL

 

[powderider87]

same problem, it was the blower motor resistor behind the glove box.. super easy to take out, i just zipped out the 2 screws holding it in and re soldered the two solder points on the resistor (the only 2 there).