Hi all, new here. Driving a '98 Blazer LS 4x4, 4.3L Auto. 4Door bone stock (so far) had it 2 months and enjoying it immensely, however. Recently turned on A/C but no cold air. Popped hood and re-engaged AC, compressor not turning. Now I did some research/reading on other posts and from what I can tell, if the PSI is low the compressor does not engage as a safety? I can check the PSI with an A/C gauge? Is this on the silver canister back left of the engine compartment by the blower assembly? Any help would be greatly appreciated.
Only has 162,000 KM (100,000 miles) so like to keep it running well for years to come yet.

 

I'll share what I've recently learned about a/c on these trucks:

You'll need a set of manifold gauges. If you have the gauges, put the blue hose on the low side port (located on the aluminum can) and the red hose on the high side port (located on the line going from the condenser to the evaporator). You'll want to know the pressures on both sides. If the pressure is 0 then your system is empty, most likely due to a leak.

In the event that you have no pressure in the system, get a vacuum pump and pull a vacuum on the system. If the vacuum holds for more than an hour then you don't have a leak and you might be able to recharge the system. If there's a leak then you need to find it and fix it before you can recharge the system.

If the system does have some pressure in it you'll have some more options. You might be able to put some UV dye in the system to help find the leak. If you decide not to do that then take it to a shop that can safely evacuate the remaining refrigerant. I don't know about the laws up in Canada but I'm guessing they probably don't want you intentionally venting refrigerant to the atmosphere.

There is more information to learn about how the a/c system works both here on the Forum and on other sites like Automotive AC Information Forum - ACKITS.COM.

If you can get some pressure readings on your system you can post them here and we can try and help you.

Good luck!

 

OK, first off thank you Toby for your help. Been busy but finally back on the repair trail. So had the test done and the compressor is shot, leaks like crazy. 600+ for new one, 300 and change for remanufactured, or 125 for recycled.(probably best bet at this point) will get me cool again

 

Be wary of a recycled compressor. The HT6 compressors in our trucks are very susceptible to leakage from the main case seal in the middle. I'm going to be replacing the compressor on my wife's '00 Blazer very soon because it's leaking from the middle and won't hold vacuum. Any old compressor that comes from an old truck is likely to have the same problem. I would advise you to do the same thing I'm going to do on my wife's truck: get a good quality replacement compressor. Be sure you replace the receiver/dryer at the same time. I'm also going to go a step further and install a new variable orifice tube in the evaporator. I will be flushing out the evaporator and condenser as well. As long as I'm going to spend money on refrigerant I don't want to lose it all via leakage.

Good luck!

 

Looking at my compressor, it is a Delphi 6580. Are these good candidates for rebuild? Like your thinking on using a "recycled" compressor, could be throwing good money after bad. Pull the compressor and replace seals? The AC tech did a nitrogen charge and it foamed like crazy on the comp when he hit it with soapy solution.

 

I'm not familiar with the Delphi model number on this compressor. It could be the same as a Harrison HT6. Check with one of the more experienced members here on the Forum. It's definitely a good idea to get a verified good compressor.

If you decide to rebuild the compressor you have let me know. I'm curious to know what kind of a job it is to rebuild one of those.