My AC/ heater blower is only working on low and high. Is this something in the motor or the control switch?

 

what truck are you working on?


Bruce

 

Assuming a pre '97, there are a few things too look for.

Pull the climate controls, different procedure depending on year and inspect the speed switch.



Make sure the connector looks good and nothin' is melted.



If that checks out, the blower motor resistors in front of the blower could be damaged, but i don't suspect that if low works. The connection there could be damaged as well.

Haynes diagaram of how it is wired.



Adrianspeeder

 

When only high speed works, the first suspect is the resistor. But if any other speed works, it's harder to diagnose. It could be the speed switch, the wiring from it to the resistor, or the resistor connector (they're known to burn).

BTW adrian
You managed to post a photo of the RAREST A/C control of any Ford truck! That style was only used for 1.5 model years.

 

Are you sure low works? With my '93 air would blow in the vents just from driving. With the car stopped and motor off, turn on the key and turn the blower to low. If air comes out, then likely something is melted behind your control panel. If nothing comes out on any setting except for high, your resistor is bad. Search the forums for this.

 

Hey theres a chance he might have a '87-early '88, but its the only one I've had to take apart to check the connector so far. My favorite setup as well, AC clutch on any setting, air control on any setting, purdy darn cool!

Adrianspeeder

 

It's a '94. Low and high work, nothing in between.

 

I agree, totally. That's why I put it in my '83.



You've got some work ahead of you. You need to check the switch on the dash, its connector, the wires from it to the resistor, the resistor connector, & the resistor itself.