Hi all,

 

I was hoping that someone could help me diagnose my A/C problem. First...the problem is that there is no cold air, even when turned to max. The compressor clutch is not engaging. Both the high and low pressure port is reading extremely high. I can jump the clutch from the battery to see if its a clutch problem, but I wasn't sure if this would damage the compressor (given that the pressure is reading so high). Can someone help me to diagnose the problem? It's a Subaru Impreza, 2013, with 50 k.

 

Thanks!

The pressures will read high when the compressor is not running so that's normal. Make sure the little ac button is lit. Make sure the fuse is good and then check if the clutch is getting power with a test light. You'll want to check it with the car on and the AC engaged making sure the little ac button is lit. If it's getting power then the clutch is probably the culprit. You can jump it too there's no danger there although you could jump it with the car off to see if it engages. You'll hear it if it does.

If there's power.

If the clutch is the problem, you can get a clutch kit for it and you won't have to change out the whole compressor. You'll need circlip pliers I believe and make sure you put everything back the way it came out. The center lock nut can be a little tricky since the pulley will be spinning freely. I usually hit it with a small air ratchet but you may have some luck jamming a screw driver into the face plate somehow.

Perfect! Thank you. I'll dig the volt meter out

No problem. I've done way more Honda clutches than I have Subaru ones but they are quite similar if I remember correctly. Easier actually because of access. That being said, I've had some very stupid things cause a clutch to not engage. There is also a safety that won't allow the clutch to kick in if the refrigerant is too low, but i have a feeling that's not the case here.

cross your t's and dot your i's before you pull the trigger on it being the clutch. Could very well just be a fuse.

Not sure if they are the same type system but I just went through a similar issue on my 01 Outback. It turned out to be the AC relay. I put 12v to the compressor with a jumper wire and it worked like a champ. $12 at Autozone for a new relay with lifetime warranty.

Ideally you need to check pressures. Just saying it's "high" is so ambiguous ita hard to assume anything.

 

Has the AC ever worked in this car? Is this an unknown history situation or it worked perfectly one day then not the next?

Even the cheap one time use gauges are better than just saying "high" - how did you determine its "high"?

Low side pressure will be high, and high side pressure will be low - in a de-energized state. 

 

Both will usually read around 90-110 psi depending on ambient conditions - but this varies according to the system.

 

You want about 35 psi on the low side, and about 150-175 psi on the high side when running. 

 

GD

Fixed! Clutch coil was bad. Put the new one on, spaced the thing correctly, and it works like a charm. What the heck makes a clutch coil go bad? Isn't it just a magnet???

Edited March 24, 20179 yr by abstoler

Subaru Released a TSB about failed A/C compressor clutches:

 

Item Code: 10-84-16R
Title: New A/C Compressor / Clutch Assembly

This bulletin announces the availability of a new Air Conditioning compressor / clutch assembly to address customer concerns of the system not operating. Electrical windings located inside the clutch assembly have been changed to eliminate the condition. The service procedure will involve replacement of the A/C compressor and clutch as a complete assembly.

Information contained in any technical document found on the STIS web site should only be used as reference material for highly trained automotive technicians. Only automotive technicians have the training and the special tools/equipment to repair Subaru vehicles.

10-84-16
10-84-16R

They may have designed it with one size too small wire. Or not enough turns on the coil. Or a point where heat concentrated or vibration.

oh well. Thanks all. By the way, I just eyeballed the gap with a playing card. Does anyone know what the actual gap should be? One card or two? ;-)

So long as it works, I would let it be. The clutch will WEAR over time and the gap increase. But this is right out of the FSM:

 

Check the clearance of entire circumference around the drive plate and pulley.

Specification:

0.3 — 0.6 mm (0.0118 — 0.0236 in)