AC

I tried my AC today and noticed its blowing warm air out when I have on the cold settings? What could cause this and how do I fix it?

Did you give it a chance to get cold? If you did and it is still warm air, then its time for a recharge of the AC.

Ya, mine last summer blew hot air until I gave it a a recharge. My friend had a can in her trunk and refilled me and since then I have nice cool air coming through.

quote:

ORIGINAL: m00nwater

Ya, mine last summer blew hot air until I gave it a a recharge. My friend had a can in her trunk and refilled me and since then I have nice cool air coming through.

How does this work? I was just talking to a mechanic about mine, as the compressor is coming on too often, which he says means it is getting low on freon. He says for them to recharge it, the freon is $80 per lb., and it might just need one lb., but with labor it would be $151. Where does one get a can, is it anywhere near that expensive, and how easy is it to do?

Anne
'91 S-10 Blazer, 2 dr., 4.3L, 4X4
153,000 miles

You can get it from NAPA, I'm pretty sure. You can also get them to refill it for about $20-30 there, I think.

P.S. Welcome back Kat...haven't seen you in a while

I took it the shop today and they said they it would only take a 1 lb of frion and no more would go in. They said it would be about $800 to fix the AC problem (replacing the compressor and other things in there). I'm gonna wait alittle while and have it fixed.

quote:

ORIGINAL: m00nwater

You can get it from NAPA, I'm pretty sure. You can also get them to refill it for about $20-30 there, I think.

P.S. Welcome back Kat...haven't seen you in a while

Wow, that's a much cheaper way to go...... I wonder why it's so much more at the mechanic's. I hope it doesn't need more than a recharge. Here in the Pacific Northwest, we don't really need the A/C as much as some places, but we do need the defroster, which I guess is related in some way. (Both use the compressor and freon? Correct me if I'm wrong).

Thanks for the welcome back...... I've just been a little tired and busy lately.

Anne

Annekat9

you don't need the compressor or the freon for the heat, just the cold air. But you do need a good amount of rad fluid for the heat.

I need it for the defrost, right?

Not really. Not if your AC is crapped out.

It's really kind of stupid, but what happened is that years ago they found that the seals in the AC systems were drying out, cracking, and then leaking because people only used the AC about half the year. So, they wired the system so that the AC is engaged when you use the max defrost. It lubes the seals and they don't dry out during the colder weather when you're not using the AC.

To me, it's a waste of gas. They should have just put a 5 minute timer circuit on the system so that every time you started up it would engage the AC, and let it go at that.

quote:

ORIGINAL: Whittaker

It's really kind of stupid, but what happened is that years ago they found that the seals in the AC systems were drying out, cracking, and then leaking because people only used the AC about half the year. So, they wired the system so that the AC is engaged when you use the max defrost. It lubes the seals and they don't dry out during the colder weather when you're not using the AC.

Hmm, that's interesting. I know that the compressor comes on and off whenever the defroster is on, and it's annoying, so I turn it off once the windshield is defrosted. Same with the AC, I only use it when it's really warm in there. But the previous owners said they usually had one or the other on all the time. Maybe that's good, if it keeps the seals and stuff in good shape. Does seem like sort of a goofy system, though.

Anne
'91 S-10 Blazer
150,300 miles

Keeping the seals lubed up and in good shape is not the only reason for running the A/C in defrost mode. A secondary effect of any air conditioning system is the removal of moisture from the air, that's why you have a nice pool of water under your truck/car in the summer time. By running the ac during defrost, you are aiding in the removal of moisture from the in-cabin air which accelerates the defogging of the windshield. So during defrost, you are forcing heated air through the ac core where a portion of the moisture in the air is removed and runs out through the HVAC drain. So the cycling of the A/C does have another purpose which would not work very well if it were only on a timer from key-on or whatever.

I wonder what refridgerant is used in your '91 Anne... If it is R-12, that would explain the high price for a top-off. R134a is much cheaper because it is MUCH more environmentally friendly (won't kill the ozone as fast - lol). They have a new refridgerant that says it can be used in existing R-12 systems, but I cannot for the life of me remember what it is.

*EDIT* - ha yeah... FR-12 is the replacement that is good for both existing R-12 systems and R134a systems.

Thanks for the explanation, Swart. I don't know what kind is in mine or if the mechanics I was talking to had even looked it up. I will certainly keep FR-12 in mind and do some more investigation before I let them charge me $151 for a recharge. (I don't know if this price perhaps included other stuff such as diagnostic tests to see if anything else was wrong with the AC system.)

Anne