AC stoppped working Compressor cycles on/off quickly

Hey all,
Working on a 98 Windstar with front and rear air that both recently stopped working. This morning the compressor kicked in and it worked but I'm not sure if that is just a fluke. I went and got a recharge can at autozone and when I hooked it up to the low port on the accum/drier I got a pretty high reading right away. I let some off the pressure off and got the compressor to kick on and right back off now. It kicks on every 7 seconds and spins for 1-2 turns. And the pressure at the accum/drier builds up again real fast. I think it is shutting off becuse of the high pressure it creates but that is just a guess. So what part of the system has failed? The compressor clutch switch on the accum/drier or the accum/drier itself? Anyone ever experience this?

sounds like the compressor clutch or the switch that engages the clutch. The switch shouldn't be too expensive. I would suggest replacing that first.

Got the switch and am getting ready to put it on, but the sold me an inline filter as well taht is about the size of a pen refill. Where does that go? Their systems didn't say and the haynes manual is silent on it as well.


Thanks!

What theymight have sold you id the orifice tube. It goes inside the A/C line and the system needs discharged to install it. What are your gauge readings? Need low and high side readings when compressor is engaged.

Rapid compressor cycling is somewhat classic of low refrigerant, although possibly other problems. Your best bet is to get a guage set - I bought a simple set for $17.00 that attaches to either high or low (one at a time, with a removable adapter) and has a port in the middle for a can of freon. When your van is cold, you should have 60-80 psi static on both the high and low.
The switch on the receiver-dryer opens (shuts off compressor) at around 21-22 psi. and closes again I think around 40-50. I have read often where that switch was the problem. You should be able to short the contacts in the plug for that switch and "force" the compressor clutch to engage which would rule out a clutch problem. I have only had A/c clutches slip - which I could visibly verify or fail - no op at all. As to the inline filter I don't know. The A/c cycling switch should quickly screw off, and the new one screw on.

Let us know what you find out.