I recently picked up an older Hobart Handler 120 MIG welder. For the most part it seems to be in working condition, except that the feed motor is always running (whether the trigger switch is plugged in or not) from the moment the welder is turned on. The speed control on it works just fine but the motor does not shut off. When I have the trigger switch plugged in and I press it, I hear what I believe is the gas solenoid opening. I've been told the contactor could be sticking. I'm not sure what this part is. Does anyone have a picture of one?
I found one part that I believe is a relay. The part number on it was T91P5A52-24. It had two small wires and three slightly larger wires going to it. I carefully took it apart and observed it. Inside, it has a little lever arm which can touch one of two contacts and a little white cylinder (electromagnet?). When the welder is powered on, I can see this little lever arm jump over to the other contact. If I hold it at the side it defualts to when powered off, the feed motor does not run.
I do not know the history of this welder. It looks like it may have had some poorly executed wiring repairs done.
Anyway, does anyone here know anything that might help me resolve the motor always on problem? Does it sound like something is just hooked up backwards? Is something stuck? I plan to call the service center on Tuesday, but before then, I know we have some smart people here who might be able to help.
