Different A/C problem

[tbirdsps]

I turn on the a/c and can hear the clutch engage. It does not cycle on and off, engaged all the time.

Air is barely cool. The pipes to the evaporator are warm.

I always thought if the charge was low the clutch would cycle on and off but it does not. I have not connected gages to see what the pressure is. Is it possible that the clutch is not driving the compressor? If so what do I check? The system was all converted to 134a 5 years ago when the original compressor siezed. The system was cleaned, new compressor and accumulator(receiver/dryer) install and serviced.

 

[4x4junkie]

If the compressor center hub is spinning, the clutch is engaged.
A bad compressor that doesn't pump well can cause what you're describing. I'd get a set of gauges on there to see what's up with it, as it's hard to really diagnose anything without them.

 

[tbirdsps]

If the compressor center hub is spinning, the clutch is engaged.
A bad compressor that doesn't pump well can cause what you're describing. I'd get a set of gauges on there to see what's up with it, as it's hard to really diagnose anything without them.

Thanks, that's what I'm afraid of. I took the clutch center off yesterday after work and cleaned it. No evidence of it slipping but it was a little oily. The airgap was correct so gages it is.

 

[tbirdsps]

This is absolutely crazy. Like I said, Monday the a/c wasn't making any cold air and the clutch was engaged and not cycling. The tubes at the evaporator were warm, the HP hose/tube from the compressor to the condensor was hot just the way it was supposed to be.

This morning the Tbird had a big water leak so I drove the Ranger. I went out to just peak around the Ranger to see if I can see anything obvious on the Ranger a/c. Now it's making cold air again and the evap tubes are cold but now the compressor clutch cycles on and off every 15 seconds like the coolant is a bit low.

I'm so F-ing confused. Do you all think I may have had a freeze up or something? Or maybe the pressure switch has gone wonky?

 

[4x4junkie]

I don't think the switch would be the issue (if it was stuck "on", it would still be blowing cold air unless it froze up the evap maybe (though even in that case the tubes would still be cold).

I have this gauge set:
http://www.harborfreight.com/a-c-manifold-gauge-set-92649.html
For the $$$ it's not a bad deal. Except for a nicked o-ring I had to replace in the high-side fitting attachment, it's worked fine for me.

 

[v8318cid]

Gauges would be the best guide, however, if the system is running and not cycling one time then working properly later, that could be either a small restriction (debris in the system) that is able to periodically free itself, or possibly someone installed a variable expansion device (VOT for example) that is on its way out. I'd likely suspect the former.

 

[tbirdsps]

Thanks all, I haven't had time to fiddle with it. It makes the ride tolerable at this point but I'm working the Tbird at the moment. Coolant leak in a heater hose. Oh if it was a Ranger it would have been fixed by now. I'm on the lookout for the crazy engineer that decided it would be perfectly OK to have to remove the upper intake manifold to replace a $%#@ hose...

 

[press 1 for english]

If the clutch is engaged and the compressor is indeed turning it could one of these problems.

1) Low on refrigerant and the low pressure switch is stuck closed.
2) Restriction or there might be a problem with the metering device.
3) Compressor valves broken.

If you don't even know the operating pressures then find out.