We have a 1991 Sync 250 SN KB 0429xx that only works with the remote switch set to remote and using the foot pedal, not when set to panel position, trying to arc weld with it.

Im going to order a new remote-panel switch S3 ( part # 052769 ) right ? and replace that and I wonder if there is also a relay that may be a cause that I should have on hand just in case while I have it opened up?

Have fingers crossed that its not the PC board. Thanks, Dave