Looks like you've fixed it?

 

There used to be a guy that was fixing them through ebay. you could send the units to him and he would go through the controller and what i used to call the resistor pack, at least on my 2003 i had.

he did a nice job getting mine up and going again back in probably 2015.

glad to see someone fixing them still!
steve

 

It's a pic from web

 

Its a very easy job, anyone with basic soldering skills could do it.

 

Ignition off blower is running

 

A few pointers:-

• The MOSFET failures are caused by overheating due to poor heat transfer to the aluminum heatsink. The FET's case sits at +12V, so in the original design self-adhesive thermal tape was used as insulation, you can see pink-colored remnants of it stuck on your old device. The GM designers plan was to keep the heatsink at neutral voltage at the loss of some heat transfer efficiency, however this was flawed on both counts, a) the devices overheated and b) tape is not a dependable insulator.
• Insulating is not really required since Hummer vents are none conductive, heat transfer performance can be improved by using standard heat transfer compound. However the latter means the aluminum heatsink will sit at +12V which is an important decision to be made. I've tried using tape a number of times and on each occasion the FET failed aqain within a short period.
• The controller's case design is also flawed, from accurate 3D models of the original, it seams there is potentially a small gap between the MOSFET and the heatsink which tends to pull the device away. When re-mounting the device, place a 1mm layer of tape on the pcb just underneath it, this will help it press against the heatsink, another improvement.

After saying all that gobbledygook, why not by a new one? - click here

 

Some one needs to design an old school Resistor pack like cars had back in the day or they had different length springs assembly that took the load and got hot but were cooled by the blower. Once you start throwing IC's and Mosfets into the mix your asking for trouble with heat. But Alas ...the old school ways are gone....It's IC's and Transistors and Mosfets and circuit boars with Diodes and resistors and whatever else they throw in there.

But as long as we have test equipment and can get parts and can solder and trouble shoot it will keep us away from wayward women and Booz.

 

So, I have the same issue where it will blow on max speed with no matter what. I figured it's the "resitor" so I purchased an after market clone but the issue persisted is there a controller in the motor itself? Or is it likely that the resitor internal board failed. I've had my resitor repaired twice before by a company that does it as im not very electrically inclined. I'm just trying to see if I can get to the root and redesign a part of the resitor to prevent this again.

 

"resitor" is actually spelt "resistor" being an electrical resistive component, although historically called a "blower resistor" this is a misnomer, it actually

Answering your question, the fan is just a motor, no internal electronics, designing It out would be very difficult. Having studied it in extremely great detail the answers are the same as I posted earlier in this thread, just buy a new one