F150 climate control fan stuck on one speed

[pikespeakviewer]

I've asked on a Ford Forum, but they are much slower at responding...

2013 F150 3.7 EcoBoost

My heating/air conditioner fan is stuck on one speed, and when I turn off the fan it goes into high mode.

I've checked the pin connectors and the power and ground provide good voltage. When I test the speed control and ground, the voltage gets lower the higher the fan speed, which I think is the opposite of what it's supposed to do.

I've changed the blower motor resistor, but no change in the fan. Where do I check next? The blower motor?

[chuckster57]

Depending on the price and how long it would take, I might change it to rule it out. But it sure seems odd that lower voltage would cause higher RPMs.

[8upbowhunter]

Maybe the blower motor speed controller.

https://m.youtube.com/watch?v=8PMgw0-Mk2I

[pikespeakviewer]

Thanks everyone. That was one of the videos I watched to figure out how to change the speed controller.

I ended up unplugging the blower motor itself and tested the pins going to it. They were all fine. I plugged everything back in, said a few choice words and headed to get groceries.

When I got 1/2 way to the store I realized how hot it was and that my fan was off. Thinking the worse, I held my breath and turned the climate control on, and to my surprise, it worked as expected! All my fan speeds are there and the original parts are back in. I was able to return the replacement part (thankfully the guy at the parts counter was proud of me for trying to figure things out with a deployed hubby). I figure that something must have been loose and re-seating everything worked, for now at least.
Thanks for all your help!

[NH_Bulldog]

I had a similar problem with my last Ford vehicle where fan would only work on one speed. It tended to be intermittent so I replaced the blower motor speed controller and it solved the problem for good