I have a old Airco 300 Heliwelder IV machine. I have just ordered a new reactor pwb for replacement and apprehensive to power the unit up. I need to know what color wires go to the 25 Amp bridge rectifier mounted directly above the reactor board. There are four wires, colors are blue, white, red & black. I know the white & blue go to the AC terminals. Does anyone know the correct wiring for the red & black leads? I have a picture of the wires in question. If anyone knows some type of an answer, I would greatly appreciate your comment or suggestions.
Thank you for your time.