2001 Tahoe A/C Problem (after 2 week non op)

[kgreg99]

Hi, My 2001 Tahoe A/C has worked flawlessly for all 112K miles since I purchased. I went on vacation for two weeks. When I returned, she started right up but the A/C doesn't seem to cool anymore.
All the control functions seem to be working (fans, LED's, temp controls) but no cold air anymore.

Any ideas?

Thanks!

 

[tahoebill]

first thing to do, put a/c gauges on, check pressure, anything less then 30lbs low pressure switch will not allow compressor to kick on, most times (except) hose, evaporates leak, front & or rear.

 

[MO Viet Vet]

If pressure looks ok you can unplug the low pressure cycling switch at the drier and cross it with a paper clip. The compressor should kick on and if then blows cold then replace the switch. Likely though you are low on R-134A refrigerant. If you see moisture at the threaded fittings then that is likely the leak source. The moisture is a/c oil. Check all fittings. You may see a bubbled hose close to the crimp that is leaking.

 

[kgreg99]

Thanks for the feedback.. Gage pressure was 100PSi
Checked all fuses and relays, all were good. We put power to a/c unit and grounded out. Did It with engine off and ignition switch off.

I'll try and find the pressure cycling switch this evening.
Thanks again
Ken

 

[MO Viet Vet]

If you have 100 psi on both high and low pressure with the compressor not engaged I would say your system is full. The drier will have only one switch screwed in to it at a threaded port. That is the low pressure cycling switch and they are known for problems. Unplug and cross with a paper clip and see if compressor comes on. You should just have the rest of all electrical connections plugged in like normal.