Question;

Prelude: yesterday, 90+°F drove to the park with my car, A/C on, ice cold like normal. Park the car, go for a 20 minute walk. When I return the A/c kicks in but after about a minute I notice the hvac air becoming warmer, figure the A/C disengaged at the this point and I was feeling the residuals of the evap warming up. Did some debugging in the last couple hours here and these are my findings:

Clutch not engaging though the car is commanding it.
- Fuse good
- swapped A/C relay with fuel pump relay - no change
- Measured voltage at A/C clutch with multimeter 14ish volts, good when the A/c is commanded on, 0V when off.

- Measured resistance across the A/c Clutch coil, open circuit. Measured a couple different times.
- conclude that the pressure sensor is good since the BCM is still commanding the clutch to enable.
- checked to make sure the compressor is still freely moving. Check. good.
- figured if compressor froze the belt would have been destroyed.

Now here is the question: Can I swap on a new A/C clutch without removing the compressor for the lines. Are there any special tools that I need, has anybody done this before with some insight? I have access to a lift, and have swapped engines in my car before so I am comfortable getting dirty / involved with it. I do not remember how much play is allowed in the AC compressor though, I know I moved it off to the side when I pulled the motor, just cannot remember the amount of freedom, if somebody could comment on this it would be greatly appreciated.

Thanks!

 

Before any of that, if your coolant temp says ---* then that's your problem. The thermostat has failed in that case. In fact, if the car doesn't reach operating temps in the proper amount of time the A/C will stop working entirely.

 

Still have coolant temperature.

The car is signaling to enable the clutch, 14v measured at the AC clutch.

 

Alright follow up and closure;

You indeed can change the pulley fairly simply. I used a lift but jacking up the front end should equally work.

Proceedure:
1.) Lift front of vehicle
2.) Remove passenger tire
3.) Unbolt water splash guard, this is the plastic cover that starts at the top of the wheel well and goes all the way to the front passenger side of the bumper. To remove this you will need to remove a bunch of 7mm screws IIRC and a couple body pins.
4.) Remove serpentine belt, may be ideal to install a new one depending on the condition / mileage on the current one.
5.)Unbolt the three bolts (3) that hold on the AC compressor, 13mm IIRC, the top one, below the starter, is the longest.
6.) You will need to buy/rent/fabricate some sort of tool to hold the compressor clutch in place, I made mine. Basically a modified crescent wrench with two holes and bolts threaded through to hold it.
7.) Position clutch holder so that the wrench arm is against the sub frame
8.) Using a socket remove the center bolt, its not all that tight, would say around 30ft-lbs or so
9.) Remove the outermost clutch face, should slide off, Note spacer washer sequence
10.) Remove the large snap ring and dust shield, dust shield can be pulled out with a dental pick or screwdriver
11.) Pull the main body of the clutch out, the piece with the belt drive. Took some convincing with a punch and hammer but nothing too crazy, couple taps and it was coming off. Heads up, I bolted two of the Compressor mount bolts back in to hold the compressor body in place while I did this, then unbolted them after to completely remove the part.
12.) Remove the next snap ring and wiring pig tail
13.) Remove the clutch voice coil (windings), again I remounted the compressor mounting bolts to hold it in place while I gave it a couple taps with a punch and hammer.
14.) With the AC compressor unbolted reassemble the new parts in the reverse order, neglecting the hammer. I found that the biggest pain were the snap rings.
15.) Put back together the rest of the car, splash guards, tire, serpentine, and mount AC as you found it. I didn't per say torque anything, just reasonably tightened things to the level that they were initially at.
15.) Enjoy your AC!


How did I diagnose my original problem?
1.) AC quit on hottest possible day ever
2.) Complained
3.) Checked fuses - easiest
4.) Checked voltage at AC Clutch connector going to the chassis wiring NOT the Clutch side! - if at battery voltage (12-15v) should be good, make sure you have the AC commanded on in your cabin! This can be done with a multi meter set to DC and putting the probes across each connector terminal, IE.: black to black and red to green, no worry if you have it backwards the multi meter will only show a negative value instead of the positive value, still works. If it is NOT commanding battery voltage then you have another issue, perhaps AC pressure too high or too low, both of which are out of the scope of this procedure.
5.) Measure resistance of AC Clutch voice coil, this can be done by using a multi meter set to resistance, scale the multi meter appropriately, ideally the resistance is 5ohm or less. Put the probes to the AC Clutch connector terminals I.E.: Red to green, black to black, for resistance, orientation doesn't matter. If it reads infinite, out of range, or basically anything that isn't a resistance your AC clutch voice coil is probably bad, for reference mine read infinite and my new clutch read 1.2 Ohms.

As always I am not responsible for anything you do to your car and anything that you do do to your car is at your own risk!