TSB for replacing the blower control module?

[mbed]

Same boat for me, HVAC blows in front but I can't control the speed. I got a blower motor resistor (non OEM) it worked but not at the high speed....

...OEM resistor I found online looked similar but with only one thin black sheet of metal. The one in my expedition looks just like the pic above....

Do you guys recommend taking the current resistor I have into a dealership and ordering from them. I'm a bad combination of cheap and not good with cars.

2007 Expedition Limited

the one with one thin sheet is for non-automatic temp control (I believe)

 

[Govt-Cheese]

I would add a WPT900 to that list.

The issue isn't likely that the blower motor is drawing too much power, but that the ground is subpar, and creating resistance which is causing the heat issues. Much like the crappy wiring in the A/C seats, you'll note on the replacement for that connector, the grounding is significantly beefed up.

Replacing the HBCM, motor, and splicing in a new connector will not fix the issue that the ground is subpar.

In fact, I would try replacing the ground with the WPT900 before I purchased the WPT688, unless you notice clear heat damage on the WPT688. If the issue persists after installing the WPT900 as per the TSB, my next troubleshooting step would be to replace the WPT688, if that fails, I would purchase a new HBCM, my last step would be the blower motor.

If you're going to spend the money on the HBCM, do the WPT900 too. You wouldn't want to burn out another HBCM before identifying and resolving the potential root cause (bad ground).

Here's a photo of the WPT900, as you can see, if attaches inline on the C297 ground line and adds a beefy ground to the frame.
View attachment 59221

I am trying to properly install the TSB 08-9-1. Does anyone know which ground is the C297? I pulled that RH trim panel and there are a couple grounds going to a stud but the wires aren't labeled. Thanks in advance.