The AC quit blowing cold today. The temperature **** was being stopped by a few broken pieces of plastic from turning all the way over to cold so I removed those and it goes through it's full range of motion now, but it the compressor still won't kick on. I also checked the r134a pressure on the low side and it looks fine.

The AC was working just fine a couple days ago. What could cause it to quit like this suddenly? I have a feeling the HVAC control panel might be the culprit since it is a bit bashed up. However, the **** makes the heat work just fine. Do I need to reset the ECM? What other diagnostic tests can I do to trace the fault?

 

OK update on the situation. The compressor is cycling on and off now, but still not blowing cold, so I hooked up the pressure gauge to the low side port and now it indicates low pressure when the compressor comes on but it goes back to normal when it's off. I'm assuming I need to look at the pressure while the compressor is engaged. Correct?

This would mean the AC is low on r134a right?

 

Correct. When you shut the A/C off the pressures equalize. What is the pressure reading while the compressor is running and at what outside temp?

 

I recharged it with a 12 oz can of r134a just a while ago. I quit at 45 psi (it was probably around 85F maybe 90 out in the sun where I was working) and it took pretty much the whole can. Doesn't seem to blow as cold as it did earlier but it could just be my imagination. There's obviously a leak in it somewhere so the next step is to track it down.

 

I believe your year blazer uses the HT6 compressor. Check for leaks there as it has been prone to leak at the body seams of the compressor. Let us know what you find out.

 

Had it checked for leaks and it is indeed the compressor that's leaking. Is a rebuild kit available for these compressors? If not, what's the best way out? Cost is concern right now. The shop quoted $466 (excluding labor and recharging) for a compressor kit including dehydrator and orifice tube with 3 yr warranty, but that's way out of my reach right now

 

I had a compressor leak about a can a week and I put in a can of super seal it is about 24.00 at walmart just make sure you follow directions ,,,, Its been 7 months and still not leaking.
I have to have air here in florida it feels like a steam bath about 10 months of the year.
Good luck with SUPER SEAL