The air conditioning will turn on no problem and then after maybe 10 minutes start blowing warm air. When this happens the clutch in the compressor is disengaged. I swapped the AC relay under the hood and still the same issue. I know very little about this system. I had it looked at and the pressure in the system is good with no leaks. Mechanic suggested looking at the low side pressure switch. He is thinking aside from that the clutch bearings might be heating up and kicking it out. The clutch is very hot to the touch after running. Anyone know how I could further diagnose this?

 

Check the clutch gap clearance. The electric clutch will not overcome a very wide gap, and as it wears it can slip, or not turn the compressor.

Monitor PID 0906 (220906) [Formula Bit(A:7)] with Torque Pro. Clutch should be engaged when On - (Bit 7 True) when A/C cycles ON. That is ALL things (A/C setting, relay, pressure switch, PCM, everything) calling for A/C.

 

Assuming I am of below average intelligence, could you lay out that PID according to how I would enter it into torque pro so I can figure out?

 

Sure - wholly without assumption though.

For anyone unfamiliar with Torque - From the main screen select >Settings, >Manage extra PIDs/Sensors, then press the three dots (Menu) and select > Add custom PID, > OK and enter the following fields:

Mode/PID : 220906
Long Name: _Air Conditioning Clutch State
Short Name: _A/CCS
Min value: 0.0
Max Value: 1.0
Scale Factor: (leave blank)
Unit Type: On/Off
Equation: Bit(A:7)
OBD Header: Auto
Diagnostic start command: (leave blank)
Diagnostic stop command: (leave blank)
Overrides PID: (leave blank)
Remember equation function data: (leave blank)

You can use the "TEST" button to operate or test the PID immediately and see the live response(s). Then throw away the PID by pressing the "Cancel" button, ---OR---
Press the "OK" button and the PID is saved/added to the list of Custom PIDs, from which you can select it by its "Long Name" when you ADD a gauge to any dashboard.

Hope this helps.

---------------- the 'three dots' (Menu) appears in the upper right of the Manage extra PIDs/Sensors screen
Also, The long name and short name are free form - use what you wish. I like to start them with an underscore so "MY CUSTOM PIDS" appear in the front of all those default custom PIDS provided with torque custom pid lists. FWIW.

 

Sounds like the classic symptom of a worn clutch plate/ too large air gap. You could mess around with trying to measure pids but in this case I would go straight to the ac clutch. Lay underneath with a feeler gauge and see how big the air gap is. It should be about .020" if you have like a 16th of an inch that could be your problem and you need to take the plate off the front remove the shim washer and reinstall the plate.

if you don't have a feeler gauge set or a spark plug gauge you can use to measure you can fold a piece of paper several times. If you fold a regular piece of paper that is .003-004" thick so that you have about 5 or 6 layers that's about how wide the gap should be..

 

And just to add some data points I replaced my compressor last summer due to it leaking from.the case, but before I figured that out my air gap was around .065" iirc, after removing the shim washer it was around .025" the clutch was still working as far as I know at .065 but maybe it wouldn't have been if the refrigerant wasn't leaking out..

on the new compressor the clutch gap is right at .019".

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Unless you're OLD and STIFF like me - and you'd have to have someone around to help you getting back out from underneath there. LOL

 

.062 fit in snug. So you say there are removable shims behind the plate?

 

The PID says ON before I even start the truck.

 

Just to be 100% sure that I was measuring the correct spot for the air gap I turned the key forward, engine not running, and went under the truck. Had a partner turn the A/C on. Clutch did not engage but I could hear air blowing inside the cab. Turned the engine on and put on the A/C and the clutch engaged. Shouldn't it engage with the key forward?