Saving2ndBass

I have a 2000 Chevy Tahoe, I have been having issues with the A/C lately. The rear A/C has never blown cold since I purchased it (1/2023) and even though it shows that it's full of freon, the A/C doesn't get cold. the compressor works and it comes on when I turn the A/C on, I've checked relays and fuses, what should my next step be?

tech2

how did you verify the charge level? pressure gauges are not an accurate way to verify charge levels bc its temp dependent. I've seen static pressures over 50psi and the system was near empty when recovered by weight.

the compressor engages...the low side metal lines should be cold...the high side hot....feel them...if no cold hose...recover the system and verify the charge level by weight.

the fact that the compressor engages means the system has some charge in it and the pcm is commanding the system on. The next step after verifying proper charge is to verify the high and low side pressures with the system running. If the pressures are very high...confirm the ac condenser fan is working.

mountainmanjoe

You mean the air coming out isn't cold? That could just be a bad temperature blend door.

Or have you touched the AC evaporator core/pipes, and they're not cold?

Bshawn911

It's most likely the blend door actuator in the rear, same thing that is a matter with my 01 yukon. Fairly easy to do the hardest part is popping off all the trim to get to the actuator. Good luck

Cusser

1. The only real way to determine if the refrigerant charge is correct is to have a REAL AC shop (independent ASE mechanic) pull out the refrigerant and weigh it. If low, they should add the full charge of refrigerant and some UV dye.
2. A service gauge set cannot determine the amount of refrigerant, even when both low side and high side are measured at 200 rpm.
3. A stooooopid single gauge on a refrigerant can is even worse than #2, useless. And many of such things contain sealer in their refrigerant, absolutely avoid those.
4. REMINDER TO NEVER ADD SEALER OR REFRIGERANT CONTAINING SEALER TO A SYSTEM. Notice the capitals.


On my 2005 Yukon, I had to grind a 5.5mm socket shorter at both ends to get the lower panel off to get to an actuator to replace it; was definitely the toughest part !