1972 miller big 40

[roxann31]

was welding with my big 40 and it stopped welding. when i change coarse amperage dial it sparks and loads engine. i installed updated supressor and same thing. any help would be great.

[Weld dr]

Serial number ??

[roxann31]

i fixed it. it had a bad stright polarity diode. she works great now. martin welding machine repair had the parts in hammond indiana. tommy is the man

[Sberry]

Good fix and glad you found handy help.