Ford Ranger AC Question... random AC clutch engagement...

Okay, I'm a bit confused.

I have a '93 Ford Ranger V-6, 3.0 (FI) automatic that I've had for a few years. The air conditioning has never worked that I can remember. I assume it needs to be recharged, but I've never looked into it. It could have absolutely no refrigerant for all I know. I've never been a big fan of AC in cars.

The problem is this. When the engine is running the AC clutch on the front of the pump will engage for a few moments then disengage. Engage then disengage. Engage then disengage. The engine slows down a bit each time indicating that it is really engaging and using a bit of my precious horsepower.

It doesn't matter where the climate controls are set, but if I turn the AC on and off a bunch of times sometimes the endless engage/disengage thing will stop. Like I can get it to stop sometimes by messing with the switch. Not always, just sometimes.

I'm not sure if this is happening all the time, as I can't hear the noise on the road, just at stoplights and such.

Where would I be looking to fix this problem?

Would recharging the AC and getting it to a baseline level stop the compressor from trying to compress?

Why the hell is it trying to compress when the AC is off?

Is there a wacked-out pressure switch somewhere?

Is it okay to just unplug the AC pump?

Thanks for any help.

~e.

Reply to
visions of effty
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If all you're looking for is to stop the clutch from engaging, by all means just disconnect the clutch- there should be a single wire coming from behind the pulley. Just unplug that and tie it off where it won't get caught in the pulley/belt. If you want it to work right, it would be best for you to take the Ranger to a service tech and have them check it out. The A/C is also used in the defrost cycle to deliver dry air to the windshield.

SC Tom

Reply to
SC Tom

The "engage" takes place when the Climate Control calls for cooling. The "disengage" likely takes place when the lo-pressure switch trips, usually due to insufficient refrigerant.

Either "AC" or "Defrost" can call for cooling. If you can live w/o either, just shut 'em off and see if the AC clutch still engages. If so, you likely have a problem with CC switching.

I think you can also disconnect a wire at the compressor if necessary, but that'd be my last choice.

Good idea to chase the issue down: the compressor can be a *serious* drag on the motor.

Cheers, Pudd>Okay, I'm a bit confused.

Pease pudding hot, Pease pudding cold, Pease pudding in the pot Nine days old.

Reply to
Puddin' Man

I've been reading up on it in some other threads and this seems to be the case. The fact that it just started happening kinda makes me think there's a slow leak in there somewhere, and if that's the case I'd rather not dump more refrigerant in it. Perhaps it sat too long before I bought it. I've read that that can make the seals where the refrigerant is go bad and cause leaks.

Aha! I didn't know this. This makes sense. I thought I was switching the thing off, but I noticed that the two settings furthest to the right on the climate slider both have defrost. The middle settings (just the blower) seem to work without the AC clutch cycling.

I really wouldn't have realized that on my own! So thanks!

I wonder if it's worth having fixed just to have defrost? How does defrost work on cars without AC?

Yeah. It's only a 3L. I need all the hp I can coax from it!

Cheers!

~e.

Reply to
visions of effty

I've heard similar.

I used to have a house AC'd hold a charge in summer but lose maybe 40% (r22) in winter b/c of lack of use. I suspected seals.

I've forgotten myself but was reminded when I set "defrost", felt the cool air.

If it's an R134A system (read the stickers under the hood) it *could* be as easy as adding refrigerant and maybe some lubricant (maybe, perhaps). I dunno about R12 anymore.

Not sure there are any anymore. Just runs the blower?

I'm guessing that if the CC is set to cool (and you have AC), it tries to cool. If set for heat it tries to heat. Both with blower, of course.

I'm not that knowledgable about Climate Control. Maybe someone better informed can come to my rescue. Or you can start a new thread.

Prost, Puddin'

Pease pudding hot, Pease pudding cold, Pease pudding in the pot Nine days old.

Reply to
Puddin' Man

Man, you're real close Puddin'. You know more than you thought you did.;) The compressor shaft seal can fail due to lack of lube in a system that isn't used much. Since you didn't know about the different settings, you've probably been using the AC and didn't know it. Your leak "could" be from the shaft seal, but it is more likely to be an oring in one of the line fittings (spring lock type). The operating strategy is a little more complex than AC=cold and Heat=hot. The AC runs in Defrost to dehumidify the air and remove fog quicker. On cars without AC, it just takes longer to defog. On a really damp rainy day a non AC car may not defog well at all. The AC\Defrost strategy also has the side benefit of not letting the AC system sit idle during the winter months. Your 93 Ranger will likely have an R-12 system as 93 and 94 were transition years. Check the tag under the hood to be sure. If it's R134 it should be a pretty easy fix (your compressor seems to be ok). If it's R12, it could get pricy to stay with R12 or convert to R134. The good news is that your R12 system was probably designed for the (then) upcoming change to R134, and would convert well. A competent DIYer can do it with a little guidance. If you don't want to spend the money to fix it, unplug the compressor to disable it. Since you don't really care about AC for cooling, see how defrost works on damp days, rainy days, etc. If you don't like the performance then think about repairing the AC. With the compressor disabled there is no drag on the engine from the AC, the pulley is just an idler. Myself, I would fix the AC if the truck is decent and dependable. When I was younger I didn't care about AC, but now that I'm a bit older I gotta have it or I get cranky. ;) Regards, Tom

Reply to
Tom Adkins

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