Just bought a 1988 Custom Cruiser, the AC compressor won’t come on. Replaced the relay under the hood. Not sure how to pull the dash panel off to look at the selector switch. Any advice would be appreciated

 

Yeah, before wasting money replacing parts that aren't bad, do some troubleshooting. Start by checking the pressure in the system. If the freon is low, the compressor clutch won't engage.

 

I don’t have access to R12 refrigerant, I’m not getting voltage on the wires that plug into the compressor, would that still be the case?

 

How about looking at a factory service manual and wiring diagram? If you do, you'll find that the power to the compressor clutch passes through a pressure switch. As I said above, insufficient freon in the system means that you don't get power to the compressor. The fact that you don't have access to R12 doesn't mean that isn't the problem. I see an R134 changeover in your future.

 

Joe is right, though he has been right so many times he sometimes forgets to fill in the small blanks for first timers. The power for the compressor comes from the A/C switch in the dash, goes through a low pressure switch somewhere in the refrigerant lines, and then to the clutch. If the refrigerant has leaked out enough for the low pressure switch to shut off, you now have the problem of having to convert to R-134 refrigerant in order to have A/C in your car because you don't have access to R-12. It is not terribly expensive if you can research how to do it yourself but you MUST have the remaining R-12 refrigerant recovered from your system by a certified shop. Change the seals and oil in your system, have it vacuumed clean, and recharged with new R-134 refrigerant. It sounds a lot more complicated than it really is.

 

Thanks, the compressor says R 12 on it but on fuether inspection the ports are for 134. It took 2 pounds, was basically empty. Blows cool now, not as cold as I would like, but better than nothing.

 

There is a pressure adjustment in the POA valve that should be made when switching to R134. It's possible that adjustment was not made when the system was converted to R134.

 

Thanks, any easy way to determine if it was done or better left to the pros?

 

I don’t really know how to check for the adjustment. I would first ensure the high and low side pressures are correct for R134. The system needs a smaller amount of R134 vs R12 but I don’t know the exact amount.

 

The best way to check for proper fill with R-134 is to check pressures with a gauge set with the system running. A cheap set from Harbor Freight or Amazon will work just fine and you can research what your pressures should be for what the temperature is where you are. Too much refrigerant will cause very high pressures in the system and too low refrigerant will obviously cause low pressures. R-12 refrigerant had a very wide acceptable operating pressure range but not so with R-134. Too high or low on the refrigerant will cause poor cooling. Once you hit the "sweet spot" it will cool a lot better. There is a sticky at the top of the General Discussion forum that shows how to calibrate the POA valve but it has to be off the car to do it. It will still work whether it was calibrated for R-134 or not, just not as well.

 

All good information. I appreciate everyone’s help and will let you know when I get it resolved. The other problem I’m working on is the passenger front window. The door is not original to the vehicle judging by the different color paint underneath the interior panel, and I’ve had a hell of a time finding the right guide that clips to the top of the glass. Finally tried one intended for mid 90s models and it fits better than any other Doorman guides, but the glass still won’t square up with the frame. The front end of the glass keeps dropping and ends up leaving a gap when rolled up. Will I need to just replace the track linkage for a better fit?

 

You are not going to get very good coverage &/or assistance/help with a door glass gap track linkage question in a post titled AC Compressor.

I suggest you create a separate post in an appropriate forum section which should yield a far larger audience to assist you.