Automotive Air Conditioning Information Forum

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 locations, running refrigerant hoses, mounting evaporator, etc.). The evaporator kit was dated 1976 and shows a part number of 98-261. I searched online but could not find any information on this unit. Currently, operating the AC controls has no effect other than blowing air. The air temp is not effected by turning the temperature knob and is constantly warm. My first thought is that the refrigerant could be low and needs to be recharged. I'm assuming this is R12 refrigerant. Is this something I could do from home or would it need to be taken into a mechanic to be charged? Any other items I need to be looking at? Any other info, tips, suggestions, and even general BS would be appreciated! Thanks.

Electrical & refrigerant are good starting points.

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

A simple test light will work. Just need to see if and follow the power circuit. Make sure you have power to the clutch or if you have a PS, it has power to at least one side. If that is the case, could be refrigerant.

You need a proper refrigerant level and power to the clutch. If not, time to track down where the issue is at.

Does the inside evaporator have hoses to bring the cool air to the driver's seatside? It may be a simple electrical add on system. Do the controls have a knob for fan and speeds and another for cooling level? Some photos would be helpful. The Ac electrical system maybe very simple. I am thinking the compressor was the aluminum 210

I'm not clear on something. Is the evaporator kit you mentioned actually connected to a compressor, condenser, etcetera, under the hood or is it installed in the cabin and just sitting there not connected to anything other than the electrical wiring for the blower motor?