Update. Still chasing a banging coming from the Surge Guard 40250. All loads inside seem to be working fine on Generator power only, TV, microwave, AC W/Heat strips. Removed Surge Guard cover and I can see the contactor connected to the Generator input vibrating consistent with the audible bang. I can put an insulated screw driver on the visible portion of the vibrating contactor and stop the vibration and noise. No visible indication of problem, no burn marks or loose pieces, connections are all tight. However, when running the generator and looking at the Aladdin screen I see "AC LEG1 123 VAC AMP 0.0 FRQ 60, AC LEG2 122 VAC AMP 20.0 FRQ 60 Gen-Set Power Selected. QUESTION, should I see Amperage on both legs? Sorry if this is a dumb question, I'm a rookie at electrical problems.