Hello, all

As the title suggests, I'm having issues with my blower motor. It only works on the low speed and it was very squeaky/noisy going in to last winter. I don't drive the car after the snow flies until the roads are salt-free in the spring, and in the good weather, I just tend to drive with the windows down.

Knowing that there's at least SOME issue with the blower motor itself, I went to the junkyard this morning and pulled a blower motor out of a 1997 Volvo 850 (not a fun job). There aren't detailed instructions on this on the forums anymore. There is an old post, but the photo links no longer work.

Long story short, I was able to swap the Volvo blower motor into my car by using the original Mercedes plastic HVAC motor mount housing, the original electrical connector from my car, and the fan blade cage from my motor.

The new motor runs strong when jumpered directly off my battery, but runs only on low speed when installed in the car (I assume that the replacement motor solves at least the noise issue I was having).

So, what do I look at next? Is there a relay or resistor somewhere in the system? If so, where? Should I suspect the rotary switch itself?


Worst case scenario, I can run a new fused wire and switch directly from the battery to turn the fan on to high speed when I want to. But, if it's easy and cheap enough, I'd like to get it working correctly. Any advice would be appreciated.



Incidentally, I will be posting a video of swapping in the Volvo motor to my Youtube channel. I'll post a link here when it's ready.