AC Compressor Clutch not kicking in

[Fuddt]

Hi. I have a 2006 997S. Hopefully someone here can help. A few weeks back my AC started blowing warm air at idle. Added a few ounces of R134 like last year but no help. Low pressure port at 47psi with engine off. Has remained this pressure for several weeks. Just noticed clutch not engaging with full AC on. Could this be a relay? Fuses check ok. Any ideas before take to shop??? Thanks.

[Dmitry at Pelican Parts]

Hello and welcome to the forum! Have you tried pulling any fault codes to see what comes up? This might be a good place to start, as it may lead you to where the issue is coming from. Let us know if you have any other questions.

[Fuddt]

Fault code for 8033 pressure sensor. Ordered sensor and will update once I install it.

[Bigtoe32067]

The fault code for the sensor tripped because the AC was commanded on and the clutch didn’t engage so pressure never changed it’s not the sensor.
The clutch didn’t engage because of potentially many things, low Freon, clutch bad, relay bad, fuse blown, control head faulty, hvac module, etc... send power and ground directly to the clutch and see if it engages and then if it blows cold. If it does you know it’s electrical. Check fuses, relays, etc...
Tony

[Steam Driver]

I agree with Bigtoe. Jumper around the switch and see if it the compressor runs. If it does then clutch is OK. If it runs, does it blow cold? If so then Freon probably OK. If it doesn’t blow cold then Freon likely low enough to where pressure switch has compressor cut out.

Why does the computer think the switch is bad, I wonder? Because it’s open? Is there another place it is checking Freon level and so knows it’s OK and switch is not? Unlikely. I think low Freon a far more likely suspect than the switch. And the system will have to be pumped down to replace the switch anyway. So my take as a “semi-A/C guy” look at the Freon side first.