Hi, I have wanted one of these welders for a long time since I tested one about 15 years ago. I finally snagged one for cheap, but the wire feed is slow. When I test voltage to the motor it's . 8 volts minimum and only 3 volts maximum for a 12 volt motor. So the power supply to the motor is failing.

I checked the liner, the gear box, motor and everything else is fine. The motor is just not getting enough voltage.

The AC transformer is outputting fine. So there's an issue between the output of the AC transformer and the motor. Well current and voltage are fine.

Does anyone know anything about diagnosing a relatively simple variable DC power supply... If I have to remove every component and test individually I will but any experience is helpful.