Thanks, Tim. Complete novice here. What would I need to do to check the electrical? I have a standard volt meter...

I just purchased a '77 G20 camper van. It appears that the van did not originally have any AC (on the engine side of things; the camper has a roof mounted AC for use when parked). However, at some point an evaporator kit was installed (I have the installation instructions for the kit - cutting vent ...