Trailblazer 325 does not increase RPM

[baymee]

Still waiting for the salesman to order parts. I will update when I install the parts.

[baymee]

I warned the owner that I will change boards in a stati-free environment, but not knowing why one burned, I can't promise that the underlying cause won't happen again. Who knows why it happened? Not from jump-starting according to him.

Tomorrow, I'll locate that second board and see...

[baymee]

Parts will be ordered. I was wondering where the second board was. I have a pin crimper. Owner claims the battery was never jumped.

[baymee]

The stepper motor does turn free with no power. I called a Miller factory service rep and he told me a few things and I found out some other info. If you know the search words, you get more info.

I noticed a burn mark on the cover that shields the PC board up front. I had to "cut"...

[baymee]

After doing some research, the part that controls the governor is called a stepper motor, Miller part nr. 251214. What I'm looking for is what controls that motor? Is it a control board?

[baymee]

SKU 907753001 Ser. MK391541R

Trying to help out with this welder.

The start feature works well but the Auto-Speed and Run positions on the front panel don't change the RPM. I have tried other similar models and after starting, they rev up higher than idle speed with no load....