wed pak 100 arcing without the trigger being pulled

[gspiva]

The welder will arc the piece being welded without the trigger being pulled. I hear the transformer hum as soon as it is plugged in. Will troubleshoot tomorrow but just looking for suggestions on what to check.

[12V71]

The welder will arc the piece being welded without the trigger being pulled. I hear the transformer hum as soon as it is plugged in. Will troubleshoot tomorrow but just looking for suggestions on what to check.

Is this one of the cheap machines with electrically hot wire all the time the switch is on? In that case all the trigger does is control wire feeding. Or you have a contactor with stuck points.

[ronsii]

Is this one of the cheap machines with electrically hot wire all the time the switch is on? In that case all the trigger does is control wire feeding. Or you have a contactor with stuck points.

Yep, sounds like stuck contactor.

[ccawgc]

Give the relay box on the pcb a wack with a screw drive handle. Might unstick it.
If that works you will need to look into a new pcb or a way to replace the relay.
suppling the machines code number will help with more detail help.

[gspiva]

thanks to all. I replaced the contactor on pc board and welder is now working. The original contactor was stuck in "on" position