AC Question

[onemanarmy]

I've got an 81 with factory air, but it doesn't work. Hasn't worked/been used in 10 years. I want to utilize the compressor for on board air, but need to get the compressor going first. What turns the AC on inside the cab? Most compressors won't turn on without freon...that's what I'm thinking is wrong with mine. Where would you start to get this going?

Thanks

 

[ferg]

Down under the dash below the glove box is a controller with an RPM adjuster. If you have a FSM with schematic you can jumper the pressure switch and force operation of the system. Don't run it for very long, it requires oil, usually suspended in the freon. Yours should use R-12 freon.

 

[PGH854runner]

if you simply provide 12V positive to the one wire on the A/C compressor clutch it should kick on while the engine is running.......X2 on the not running it very long like that.......they dont like running on open air with no oil......ask me how i know LOL

 

[onemanarmy]

Would trying one of those home charge kits from autozone pressurize the system enough for it to cycle on?

 

[KLF]

Pouring refrigerant into a system like that seems pretty wasteful to me, if your goal is to convert it to OBA. By now all the O-rings will be all dried out and I would bet that every connection will leak.

There are many threads out on the great Interwebs on how people have done this conversion. You need to just bypass all the old wiring and go directly to the clutch by applying +12V to the single wire that comes off the clutch. As mentioned, only do this for a test, don't run it for more than a minute or so, as this type of compressor relies on the ester oil in the R12 to keep it lubricated, you will burn it up.

Once you confirm that the clutch and compressor work, you can do all the plumbing and wiring as needed. You need a high pressure limit switch, among other things. Others have solved the oiling problem by adding an oiler on the intake side, then a seperator on the discharge side.