The compressor clutch on my 2008 G35 fails to engage, so the AC blows warm air. I thought it could be the compressor clutch relay, but I've been unable to locate one in any G35 diagram. Does anybody know if there is one and where it is located? I read somewhere that it is part of the IPDM and is not a serviceable part, but I find that hard to believe.
Thanks

 

How is your freon pressure? Insufficient pressure will prevent the clutch from engaging as well, and thats usually the case most of the time.

 

Thank you for your reply.
With an outside temperature of 62 F both the low and high pressure sides are at 15 psi. Is that sign of a failed compressor?
Does it make sense to attempt a recharge it? How do I recharge it if the compressor is not working?
Thanks,

 

Had the same problem a few months back. AC clutch was bad. Installed this aftermarket
one ($65):
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

The good is that you don't need to crack the freon at all. The bad is that it's a real PITA to
replace without pulling the radiator (particularly getting the snap rings out). If you pull
the radiator, it means doing the whole freon thing.

Be sure you pay attention to the orientation when you replace the backing plate, otherwise
it won't seat properly.

Alternatively, you can replace the whole compressor.

Good luck

 

You are low on refrigerant, those pressure readings are basically an empty system. You refill from the suction port on your manifold and you have a little inspection window so you can watch the refrigerant flow through it. Watch a couple youtube videos it's not difficult, don't overcharge the system.

You probably have a leak that won't let it hold more pressure so be prepared to purge and repair.

You can use a paperclip and jumper the AC low pressure switch when filling which will turn the compressor back on. You won't get shocked it's just an open/closed switch the computer uses to verify pressure. Unplug the harness from the sensor and stick a paperclip across the two pins when everything is set up and you're ready to suck.

 

I'm having the same issue, however I definitely have sufficient charge, over 100 psi on the low side, still no function of the clutch. What should I check next?

 

1. If you haven't done so, I would check the low pressure switch (located under the radiator cover)
2. The AC clutch rely is in the computer control unit and it's not replaceable like in other cars (this is very unlikely anyway).

Turns out my problem was a shot compressor so I had to replace it.
Good luck!

 

I had the same issue with my 2007 Sedan and tried to find relays and all that to no success. My clutch wasn't actuating when it should have been so I thought it may have been a bad clutch. I went to replace it and decided to spin the compressor by hand several times to see if forcing freon through it would do anything. After starting it up and letting it run for a while, the AC started blowing cold again. I am not sure if the compressor was just stuck a little or what but that was 2 years ago and it's still blowing cold. It's free to try anyway!

 

Well, I was able to turn it by hand, a little bit of resistance, but it was nice and smooth, no feeling of fried bearings. This weekend I'll try to get in and take a look at the low pressure sensor.

 

Ok, so I investigated the low pressure switch. Checked all 3 possible combinations of connections and all showed open circuit. Couldn't find any info online as to what it should be, so I'm not sure what it's really indicating. I tried jumpering the leads to trick the IPDM into thinking the switch was closed and the only response I got was a total engine shutdown by connecting contacts 1 and 3. popped 2 codes on OBD fusion, U1240 and U1243. It also popped the VDC and SLIP lights, but those went away after 1 full ignition cycle. So, I still don't know if it's the clutch or the low pressure sensor. One thing I did notice was that while jumpering the plug to simulate the switch position, the fans never kicked on while the A/C light was on. But as soon as I plugged the switch back in the fans immediately started. This leads me to believe the issue is, in fact, the clutch. Anybody have any input?

 

What did you use to remove the pulley? I got the outer plate off and pulled the snap ring, but I can't get the pulley to budge

 

Usually you use a 3-jaw puller unless it's something like a chevy with the threads for the little pull stud. I'm pretty sure most Nissan's just use a jaw puller.

 

Just got it off couple minutes ago, carefully applied leverage and patience. Now comes the second snap ring. I'm leaving the radiator in place, no room for a 3 jaw puller

 

Repairs done.

Costs:
Clutch - $65
Tools - $10 (needed a pick set to help remove the snap rings)
Labor: $300 (6 hours at $50/hr, I work relatively cheap)
Total costs (value): $375

Quote:
Compressor - $300 (wouldn't change just the clutch)
Labor for swap - $400
Pump down, evacuate, recharge - $125
Labor for recharge - $100
Total for shop repair - $925 + tax

Total saved - $550+

Knowledge gained - good amount
Swear words uttered - ? (Likely 50+)
Knuckles busted - 1
Cabin of car - cold

All in all, happy with everything now, definitely don't want to try this if you question your mechanical ability.

Edit: Gotta pull the front plate this weekend and adjust the shims around. Currently the plate stays engaged to the pulley all the time. Luckily I rarely ever turn the fan off, so I don't have to worry about any liquid refrigerant making it back to the compressor and blowing the seals.

 

UPDATE: apparently the clutch I received wasn't exactly the right one. After shimming behind the outer plate I did an op test, first time cycled on and off great, second time it didn't engage. Upon closer inspection the magnet portion shifted and ripped out the wire. Apparently the indexing pin didn't fit snugly in the hole and the tab didn't sit correctly either. Now to order another new clutch and try again. At least this time I'll know exactly what to do.