2008 Expedition. HVAC Blower Shuts Down On Max Speed

[Bloodyknuckles1]

I have a 2008 Eddie Bauer Expedition with dual automatic controls. The blower motor works fine on all speeds but max. At max speed it stops, comes back on about 20 seconds later, stops, and continues stop/start pattern. I replaced the blower motor and resistor (control module). I don't see any burnt wires. Checked alternator & it puts out a consistent 14v. It will blow on speed 7 with engine off. I read somewhere about resetting the PCM, has anyone done this and did it work. Any ideas, Please!

 

[sjwelds]

Did you use motorcraft parts?

 

[Kevin08]

I have an 08 with the automatic hvac. It is doing the exact thing as the original poster stated. Seems to work fine on lower fan speeds, but at the highest speed it will shut the fan off with in a second or two. Fan buttons are then inop until the hvac control head is turned off then back on. Will blow as long as it’s not set to the highest fan speed. Anyone else had this issue? Is it the hvac control head dying?

 

[Motorcity muscle]

Had similar issue with my ;07, found loose wire inside a wire connector to blower housing on passenger side. Left blower on and used infa-red gun to find problem.