Blower Motor Resistor Fix: PWM

The resistors on the factory switch would be difficult because of the blower relay wire. Maybe it would have to be put on a separate switch? Any ideas?

 

So, looking at the factory diagram, I think it would be doable with a little creative reuse of the toasted blower resistor. I have a rough sketch on my tablet, I'll post it up when I get some free time.

 

Here’s an update on the project. It’s still running great! I’ve made a couple of improvements:
Here is the PWM after mounting it inside a project box and installing a low profile computer fan.

Keeps the board at whatever temp the cabin is.

$17 BUD Industries CU-3283 Plastic Style A Utility Box 6" L x 4" W x 2" D, Black

https://www.amazon.com/dp/B005T5A0W4?ref=ppx_pop_mob_ap_share

$10 Cooler Master Sleeve Bearing 80mm Silent Fan for Computer Cases and CPU Coolers

https://www.amazon.com/dp/B005C31GIA/ref=cm_sw_r_cp_api_i_2uPLCbPS092B0

 

As an update to the project, one year later and the PWM is still running the blower with no problems. Seems like a permanent fix. At least better than Toyota’s blower resistor.

 

Another update. I was experiencing some intermittent power interruptions to the blower motor. Took the box apart and found all 4 screw connections were loose. Moral of the story is to use locktite for this job! Working flawlessly again.