Air Conditioning

[smshirk@bellsouth.]

My 93 full size blazer's AC did not work when I turned it on for the first time since last fall. The compressor is not coming on. both fuses are good. I have a wiring diagram that shows a relay, but does not say where it is located. I think I have an electrical problem becaue I cannot hear or "feel" the compressor. The hose feel test does not indicate a bad compressor. My system is still R12. Any help appreciated.

[rlith]

have you tested the pressure?

[chcknugget]

On my 96 there are three relays bolted to the firewall for AC. You may want to check there.

[Rick Norwood]

Originally Posted by smshirk@bellsouth.

My 93 full size blazer's AC did not work when I turned it on for the first time since last fall. The compressor is not coming on. both fuses are good. I have a wiring diagram that shows a relay, but does not say where it is located. I think I have an electrical problem becaue I cannot hear or "feel" the compressor. The hose feel test does not indicate a bad compressor. My system is still R12. Any help appreciated.

More than likely your problem is that you have lost enough refrigerant to the point that the low pressure switch will not allow the compressor to kick on.

Since you probably can't go out and buy a 1lb. can any more, you will probably need to take it in somewhere and have the pressure checked and will probably need the system re-charged.

The trick is to try to locate the source of the leak before you loose any more freon so you don't have to keep recharging it. At $90 per pound, you want to find and correct the leak.

[rlith]

Originally Posted by chcknugget

On my 96 there are three relays bolted to the firewall for AC. You may want to check there.

Actually one of those is for the fuel pump...

[smshirk@bellsouth.]

Originally Posted by Rick Norwood

More than likely your problem is that you have lost enough refrigerant to the point that the low pressure switch will not allow the compressor to kick on. :naughty:

Since you probably can't go out and buy a 1lb. can any more, you will probably need to take it in somewhere and have the pressure checked and will probably need the system re-charged.

The trick is to try to locate the source of the leak before you loose any more freon so you don't have to keep recharging it. At $90 per pound, you want to find and correct the leak. :iceslolan

Thanks for the replies.

Rick,
I had no idea that the refrigerant level could be so low as to keep the compressor from kicking on. What you say is probably true, because I don't think it was cooling all that well last summer, although it did work. That's what happens when 2 people have 6 cars. This makes the 2nd one with no AC right now. The other was obviously low in a non closed system. The good news is that from your reply it sounds like I can still get R12. I thought I would have to convert to r34 to fix it if the freon was low. I still have one of those hoses that was used to put the little cans in with. is there any safe way to test the pressure or lack therof with the hose and clamp? There is a pretty honest mechanic close by that has treated me well before with this Blazer, so I will just take it to him I guess. It has 190k miles and I don't believe the freon has been recharged but once many moons ago.

[rlith]

Understand that if you continue to use R12 that stuff is expensive (40 bux an ounce) and your system holds 14 ounces.... You've obviously have a leak somewhere which really needs to be addressed. If you want to check the pressure go to advance autoparts (or any parts store) you can get an ac pressure gauge for 10 bux that will give you an indication of how low you are. That said, you need to find the leak. Once you find the leak, you should convert to r134 (or even Hot Shot (check with any local HVAC outfit, it's compatible with your r12 oil and much cheaper and cools better) But your leak really needs to be fixed...

[chcknugget]

Originally Posted by rlith

Actually one of those is for the fuel pump...

Sorry, my bad, haynes said they were all AC in the electrical section.

[Officer Redneck]

My last truck had the same problem. I bought a conversion kit for Wally World for about $27.00 and it came with a gauge, a can of freon that had a type of stop leak and oil already in it and a second can of freon/oil by itself. It was pretty easy it do and it worked for two years before I had to add a can of R134 but at $4.96 a can I could live with that. Just a suggestion, take it how you will.

[Rick Norwood]

Originally Posted by smshirk@bellsouth.

Thanks for the replies.

Rick,
I had no idea that the refrigerant level could be so low as to keep the compressor from kicking on. What you say is probably true, because I don't think it was cooling all that well last summer, although it did work. That's what happens when 2 people have 6 cars. This makes the 2nd one with no AC right now. The other was obviously low in a non closed system. The good news is that from your reply it sounds like I can still get R12. I thought I would have to convert to r34 to fix it if the freon was low. I still have one of those hoses that was used to put the little cans in with. is there any safe way to test the pressure or lack therof with the hose and clamp? There is a pretty honest mechanic close by that has treated me well before with this Blazer, so I will just take it to him I guess. It has 190k miles and I don't believe the freon has been recharged but once many moons ago.

I would bite the bullet and take it in to your mechanic and have a proper leak check, evacuation and re-charge done. Your leak could be something as simple as a loose connection, a bad O-ring or anything up to a bad compressor seal, which may require you to replace the compressor. They should also check the compressor oil, O-rings etc. and get you ready for summer. They will probably quote you a price for converting to R34 if you ask them to. It may be cheaper in the long run because like I said earlier, R12 ain't cheap.