I have a 1999 Tahoe LT 5.7l vortec 157000 mi and my A/C hasn't worked in years. I'm 60, getting wiser, and deserve A/C, but I have no idea where to start. last time I had A/C I had it charged at a shop and a month later it quit. I bought a 134a recharge kit and the compressor kicked in and I had A/C another month. Due to an error in judgement TheTahoe sat for 14 years, Covid-19 hit so I went out to her shed, cleaned her up, pumped her full of new fluids(all), installed a Interstate Battery (Made in the USA), then she started on the second crank blew out some rust and purred like a kitten, But NO A/C. Fixed a few wiring challanges, Vac hoses, coolant system, however summer is comming and I will need A/C. Any advice/direction would be most appreciated since I am tackling this project all by myself and know nothing on A/C (except a few You Tube vids)
Thanks in advance from an Old Fart

 

Food for thought..

In my experience, normally there is not much that does fail on aircond system.. if the gaspressure goes low, a switch shifts and it all stops.. usually due to a hole in the condenser.. since the condenser sit all the way up front in an quite enviromentally challenged area they tend to fail after 5-10 years, depending on where you live.. winter and saltdrenched roads usually hurry that process up.

The other option is if the clutch for some reason doesnt kick in as it should... there is the clutch itself and to engage it -the pressure switch, a relay and a fuse are involved.. the clutch coil can get shorted.. usually due to old age and overheated.. but that is less common.. If you have pressure in the system and the damn thing doesent engage anyway, it should be possible to engage it by pulling the control relay out and put an electrical jumper there instead.. if you get an satisfying "klick" and things are getting cold again you are homing in on the problem..

But... il guess a good start to make sure that there is no hole in the system anywhere, is to take it to a shop and have it checked for leaks.. no point to try to fill and mess with it if you have a hole somewhere.. you could ofcourse get access to the condenser and have a look at it... if it looks corroded and ****ty.. or oily and messed up in a (typically) lower corner you have most likely a hole in it.. splap on a new condser with new seals.. and take it from there..

/P

 

I hope that recharge kit did not contain a sealer/sealing agent, because (1) the system could be ruined permanently and (2) no shop will touch it.

AC is not just a simple add refrigerant fix. When the shop "fixed" it and it stopped a month later - a leak - that would've been the time to have the shop check/fix the leak(s), now you've most likely got a bigger problem.

 

You need to put in 134 that has a dye in it so you can track down the leak. UV dye makes it super easy to find a leak with a UV flashlight that comes in a kit.
Do you have rear a/c ? The lines going back to the rear like to corrode and leak also. Been there with my '99 Yukon and my '11 Tahoe.
A shop will use the UV dye, it make leak finding quick and easy. Leak sniffers are not as pinpoint as the dye.