AC conversion questions...

[gijoecam]

OK, I converted from R-12 to R-134 in my Ranger... it's a '93 4.0. Everyone I talked to (and the Midas I went to yesterday) said that all I needed to do was purge the r-12 (ahem! I mean evacuate it...) and refill it with the proper oil and r-134a. Replacing the accumulator, purging the old oil, etc was not even an issue because the new oils are compatible... well.....

I did that this afternoon, and it seems to work quite well. The compressor cycles just as it should, and the air seems quite cold (especially considering it was only about 45 here today) but here's the problem... even when I slide the selector to the off position, turn the knob off and the knob is in the out position (i.e. compressor off), the compressor continues to cycle as if it was on?!?! Any ideas? The only way I could get it to stop cycling was to unplug the pressure switch... is there something more I was supposed to do to prevent it? I would think that with both switches of, the system should never cycle at all, right?

I'm stumped... anyone have a wiring diagram for the HVAC system they could shoot me a copy of or post here? You can e-mail it to gijoecam@prodigy.net if you'd like. I'd certainly appreciate it, guys....

Thanx.

-Joe-

 

[Bill MacLeod]

Clutch Cycle Pressure Switch

If the function lever is in the defrost position, the switch will open, resulting in compressor clutch engagement when the temp. is lower than 46 F.
This is to aid in defogging and defrosting the windows.
So if you had the lever in the defrost position, then your system is functioning properly.
Info from Ford Truck Shop Manual

 

[gijoecam]

I know that... the problem is that even with the switches all off (i.e. compressor light off, fan off, and selector switch off) the compressor still cycles as though it's on...

-Joe-