magnetek 7300 converter question
I've got a 2002 28.5 wildcat 5th wheel and this past weekend we were camping plugged into 120v shore power. The problem was we had all the 120v appliances working fine but the 12v lights, fans etc... were losing power over the course of the weekend to the point of dead batteries. Today I was troubleshooting and found no bad fuses or curcuit brakers and the batteries weren't receiving a charge, I feel stupid saying this but there's a switch (looks like regular light switch) mounted beside the fridge so I flipped it on and everything is working as it should. I didn't get any of the original manuals with the trailer as I bought it used so never knew what the switch controlled, can someone explain the purpose of this switch? As far as I can tell it allows the converter to supply 120v but not 12v power when plugged into shore power.