2013 Outback AC Compressor Clutch Seems to Never Disengage

[dirty_mech]

I have a 2013 (Yaeger v.) Subaru Outback, M/T, 190k, of west coast origin that came to me with a minor amount of rust on all the pulleys at the front of the engine. 

I don't know if the rust is related, but my AC compressor clutch never seems to turn off.  The AC produces runoff year round, even with the fan totally off.  The AC works perfectly, and the fan doesn't seem to blow air conditioned air when the AC is off.  However it does produce runoff constantly, and I'm never able to visually see the clutch disengaging at the front of the engine while it's running.

It's a Denso TSE14F, which from preliminary research appears to be less common in Subarus of this model.  Already tried adjusting the clutch but I can't seem to unscrew it from the compressor.  Photos linked below.  It seemingly has a large 20+ mm nut on the front, but it doesn't protrude enough to use a socket or wrench.  Inside a dust cap in the center it has a very small, 8mm or less,  hex head that might also be a screw.  However it seems weak and I don't want to risk breaking it by using a lot of force.

Is anyone familiar with how to loosen or remove the clutch on this AC compressor for adjustment and service?  Also I considered the clutch solenoid might be stuck.  I see two electrical connectors on possible compressor solenoids, but am not sure which one engages the clutch - the black or the blue-dot one.  I'm also not clear on if the clutch solenoid is under pressure from the AC system. I read that at least one of the connected is in the refrigerant.

There's also an intermittent squeak on the front of the engine that seems to occur most often in cold and/or wet weather, and only occurs at idle speed.  I've replaced both idler pulleys and the tensioner pulley with no luck.  I'm starting to think the AC compressor might be the culprit as it's running constantly whenever the car runs.s

Perhaps I'm better just getting a new compressor? Any advice appreciated!  Having it run all the time can't be good for my compressor or MPGs.

https://imgur.com/a/yPBz4qf

[Ferret54]

IIRC this compressor uses a SWASH plate ( VARIABLE DISPLACEMENT, CONSTANT PRESSURE pumps ). There is no clutch. They move the angle of the swash plate to increase or decrease the freon pressure/flow thru the condenser or evaporator. Many newer cars are using this system.

Edited March 29 by Ferret54

[dirty_mech]

On 3/29/2024 at 11:18 AM, Ferret54 said:

IIRC this compressor uses a SWASH plate ( VARIABLE DISPLACEMENT, CONSTANT PRESSURE pumps ). There is no clutch. They move the angle of the swash plate to increase or decrease the freon pressure/flow thru the condenser or evaporator. Many newer cars are using this system.

Well that answers a lot!   Never heard of them until now. I've reviewed the technology and see there's no clutch to idle when it's off.

Still, is it normal for the AC system to produce runoff constantly when the compressor is the variable displacement type? Perhaps when they get old?

Update: Answered my own dumb questions. 

 

Guess I'm just too used to owning an older car.  The AC in fact does run even when it's not activated.  Someone online explains:

" Does the AC Compressor run when the heat is on?  Generally yes, as long as the outside temperature is above freezing and the more common settings are used. The compressor cycles on and off as its needed, the colder it is the less its needed. It serves to dry the air to keep the windows from fogging up.

All air through the hvac system is passed through the a/c coils, the coils will be cooled to within a degree or so of freezing or the closest they can get depending on the outside temperature. This collects any excess water from the air, then is routed past a blend door that directs air to mix with the heater core in varying amounts depending on how much heat is called for, either full heat, no heat at all, or any amount in between. Although the lower limit for the a/c coils is about 33F (0.5C) the upper limit of the heater core is whatever the engines operating temperature is at. Which even in winter is 190F (88C) to 230F (110C), so this will be the temperature of the heater core as well once the engine warms up, so also due to the size of the heater core (its literally a mini radiator for the engine coolant) there is multiple times more heating ability available than a/c so assuming the engine is warm enough and everything functions properly full a/c and full heat at the same time will still result in very hot and also very dry air."

So the AC doesn't even need to be turned on for the compressor to run and produce water.  It's being used to dehumidify the car.

No wonder my windows don't fog up so much!

Edited April 1 by dirty_mech