A/C no blow

The air conditioning system in my jeep has always blown very lightly, and never been cold. When set on heat, it does seem to get warmer, but still doesn't blow hard. When set on vent, it blows much harder, but still about half of what it should. The defroster vents under the windshield blow hard as hell, like the rest of em should.

The cooling system is of the 'closed' type...the radiator has been replaced, however, this has always been a problem.

i had the system changed from r12 to the 134 however that did not change anything. shortly after the conversion, i found a broken hard line running under my reserve tank, and repaired it. it didn't make a noticeable difference in my systems output.

If there's 2 things I know nothing about, that's electrical systems and a/c's. if anyone has any suggestions, please let me know. oh, and i had the system recharged again AFTER fixing the leak i found

Sounds like a vacuum problem switching vents maybe? What exactly do you mean by "hard line"?

sorry, by 'hard line' i meant a plastic hose, a vacuum hose if you will. it runs underneath the coolant reservoir

its an '89, but there is definitely something wrong, when i say it barely blows, i mean that you cannot feel it if you place your hand more than one inch from the vents, much less hear anything coming out of the vents. seriously, its that bad. yet when you turn the defroster on, you can just barely feel it when sitting in the driver seat...

Recently, I thought my heater was broken... but it was fine. The vent setting really does blow really hard as well as defrost. My AC and heat blow out about the same... so maybe it's just normal? What year? It doesn't really seem like anything's wrong... maybe just the way it is?

yeah, there's always something coming out of the vents regardless of the setting. but now that i think of it, i relocated the bottle that was behind the bumper when i put a JCR on there. i also forgot that i did find another vacuum line cracked last week next to the battery...when it gets light outside in the morning, i think i will check all of that...thanks...any more suggestions while i'm going under the hood?

X2 on a possible vacuum problem... check all those pesky plastic lines, and the bottle behind the bumper. A full failure of one of those lines would stick you on a "defroster only" setting, no matter what setting you have on the dash.

A major leak would cause all other selections to be weak, or slow. Do you still have any air coming out of the defroster, when you select heat or vent? If so, then there's a pinhole or crack in one of the plastic lines.

The first place to look is under/around the battery area, as the lines there get trashed pretty easily. Don't be afraid to tug or pull on stuff, as a "secure" line will survive- a weak one will show up as a broken tube in your hand...

1. I wouldn't consider the guy reputable in comparison to shops that do this primarily, or HVAC specialists, but he was certified to handle the stuff (i know, sometimes that's just not enough) so its very possible he didn't do it properly.

2. didn't know about the 0-rings...as i stated earlier, i'm dumb on a/c's

3. a friend also told me about that...on the 'ToDo' list now

4. I think the sealing would be a good idea on my system seeing as how its never been managed until now

5. I agree here. I ALWAYS use teflon tape in places like this.

i will check all these things out in the morning

Sorry for the 2nd message, but your questions brought back some issues I used to have, and require more thought...

Did you have your 132a conversion done by a "reputable" shop? On my 1991, I had the blessing of having an HVAC specialist helping me, and while we worked, he explained some issues with conversion jobs.

1. The system has to be fully evacuated, if ANY of the lines are "opened", no matter for how long- moisture is the enemy, and a tiny pinhole will kill your system- which is why we installed a new condensor. The entire system needs to be "swept" with a vacuum pump, for at least an hour after any repair to lines is done. ANY leaks must be repaired before servicing with R-132a.

2. The o-rings that seal connections are a different type of rubber, and they are NOT compatible. I've heard of some "good luck" stories of folks getting away with using the butyl o-rings that were originally installed, but I took no chances- I spent the $12 for a whole new set of viton o-rings, and got the experience of changing them ALL out. Money well spent. All are easily reachable, and you'll gain tons of experience for troubleshooting in the future. I was told that a more reputable shop would have given you back the old Butyl o-rings in a little baggie, with an explaination. Any missing chips or chunks out of an o-ring would be explained in #3.

3. There's an evaporator valve in-line with the evaporator, which is against the firewall, inline with the high-pressure line going into the cabin. It's just a little spring and ball valve, but it's what does the cooling magic between liquid and gaseous freon, of ANY kind. If the conversion wasn't done right, or your system is older, then there's TONS of rubber and oily junk that can jam this little valve. I took mine apart, and cleaned it all out with solvent, and dried it with compressed air. My advisor was amazed at the crap that came out of this, and blamed all my previous issues with this one valve.

4. Differing opinions on this subject- R132a WITH sealant. Some have said that it causes compressor overloading, but that would be with a leaky compressor- I used it, and it ensured that all the threaded connections were complete, and not leakers. My HVAC buddy didn't have an opinion on a "good" system, but expressed concerns about a system that was living on the fringe- any bad gaskets in the compressor would draw the sealant, and kill the compressor in short time. If you're sure everything else is sealed properly, and vaccuumed well, then a with-charge sealant is not a bad choice for an older system.

5. Teflon Tape. Some love it, others hate it, but I had GREAT success in using it on EVERY threaded line I disconnected and re-connected. We used an electronic "sniffing" device, and every joint that I used one wrap of teflon on was sealed nice and tight. The majority of fittings are aluminum, so there's lots of places where wear will kill your seal on fittings, so tape isn't such a bad idea.

Good luck, and let us know how you made out. I used to be terrified of anything with freon in it, but it really isn't that hard, with the right equipment. Now I know how to use the gauge that comes with the freon recharge kits, and know how to understand what the readings mean.