AC Fan Motor Control Resistor

[moncriefd]

2010 Ford Expedition front AC blower quit working. Had some intermittent issues and then bam... nothing. Did a little surfing and saw that the Fan Motor Speed Control resistor could be the culprit. Spent thirty minutes at the local autoparts store because my part looked different than the one on their systems. Mine looks like a metal heat sink, not the plastic card looking one.
Went home and replaced the part. Now my front AC is working again. YAHOO!!!
BUT (AND IT'S A BIG BUT :-0) When I turn the AC on to full blast it cuts off. I turn the fan speed down a notch, wait a few seconds, and it comes back on. Runs fine, unless I crank it all the way up. Seven speed settings in total. Digital readout. Dual climate control.

A few side notes. This Expedition has front and back climate control. Back works fine. It also has an "Auto" setting.
Vehicle cycles from floor, to defrost, to vents with no problems.
I can switch from outside air to recirculator with no problems.
So, in short, I kind fixed it. Speed setting 1-6 seem to work fine. Turn it up to 7 and boom. Cuts off.
Also, final side note, I have cooled front seats. If I set the fan speed to 6 and then turn on both front seat coolers, it trips the AC off, just like if I had set it to full blast.
If I knock the AC fan speed down a few more notches, AC seats work fine.

Could it be the battery/alternator not providing enough juice?
Fan sounds fine but could it be going out?
There's no cabin filter (from what I can tell) but maybe if the fan housing was clogged or dirty it would be reducing air flow over the resistor and causing it to trip off?

Any assistance is much, much appreciated.

This is the part I replaced. http://www.amazon.com/9L3z19e624b-Blower-Control-Resistor-Ford/dp/B004K8V6XS/ref=cm_cr_pr_product_top?ie=UTF8

 

[stamp11127]

Might be the wrong part even though the plug is the same.

I checked your link to Amazon and it states it does not fit a 2010 expedition....

 

[moncriefd]

Link was for visual reference. Part I picked up from auto parts store matched up on their system. I was told that it may be a fuse. Some cars run the full blast ac setting through it's own fuse.

 

[stamp11127]

The latest diagrams I have go up to 2007 so I can't say for certain about the 2010. Ford used one 40a fuse to protect the blower circuit at that year, I don't see why they would change to additional fuses.

Rock Auto shows two modules for that year, one for auto temp and the other for manual. I'd see if they gave you the incorrect one or if they show the same module for both.