Topic: A/C Blowing Warm

[Jeffy]

Well the A/C unit in a non-Jeep has been out for a while.  The owner didn't get ti fixed while under warranty and now that Dealer is gone.  (ie., closed down.)  It seems the compressor is not turning on.  The owner said the Dealer checked the pressure and it was fine.  They wanted to replace the pump and that wasn't going to happen.  So is there wany way I can check the pressure with an air gauge or do I need a special one.  (I've got a digital gauge.)  I've been told to bypass the HI and LO pressure switches to see if that does anything.  There can't be that much to the system that can go wrong if there is no leak.  Although it would be nice to confirm the pressure without buying anything.  The owner wanted to just get the system topped off  again.  Seems that sorta helps but I think the problem should be fixed rather then spend money to recharge the system every summer.

[Jeffy]

No one has A/C I guess...

[Jeffy]

Well, there might be someone who is interested in A/C.

So here's the outcome.  I jumped the low-pressure switch with a paperclip and the compressor worked.  Still blowing hot.  So that means the system is low on R-134a.  If it was the switch, and there was enough R-134a in there it should have worked.

So thins being mid-summer recharge kits of slim pickings.  Went to K-Mart, AutoZone, Pep-Boys and Kragen.  Prices vary depending on the kits.  There seems to be two different can types.  One uses a setup that white gas uses.  Screw on the tap then it punctures the top and locks on.  The other type seems to be more like a standard arisol canister.

I went with a gauge and hose setup that screwed onto the top so it is reusable.  The recharge cans seem to be easier to find then the other type.  I also noticed that not all of the kits come with gauges.  Some of the really small top-off canister's dont have them.

Also, if you're going to recharge the system, make sure you know how much refrigerant to buy.  The system I'm working on is 1.85lbs.  I bought a 10oz and a 10oz can.  I've still got to recharge the system.  It's been in the 100's for the past two weeks so I'm not looking forward to standing outside and working on it.  I'll probably get to it tomorrow.

[JBFried67]

I did this on my S10 about 2 weeks ago.  Took me all of about 10 minutes to add refrigerant and finally I have A/C again!!!  I also chose the can with the hose and gauge attached.

[Jeffy]

Well it was down to 10 psi or somthing.  I dumped most of a 19oz can into the system and got it up to 40psi.  The compressor no longer needs to be bypassed to run.  It's blowing cool air but it's not super cold.  I'm not sure if that's because it's over 100 outside or the system didn't get charged right.

The can said to keep it upright and shake occasionally.  Some people say you can pour in liquid R-134a but no more then a can worth.  The can I got is 19oz, so that would be a heck of a lot.

I think I might ahve to take it for a trip to see if it gets cooler.  I think I also found the leak.  It's at the low-pressure fill port.  It leaks out the cap!  It doesn't leak if there is something connected to it!  Tightened down the cap and hopefully it will hold pressure.

[StefanBidi]

I'm not sure if that's because it's over 100 outside or the system didn't get charged right.

I'm sure it's because of the heat.  Me, and a lot of people I know, are having the same problem.  I used to be able to leave my A/C (in the truck, not the Jeep) at 1 and "not so cold" setting a few months ago, now, depending on how long the truck's been sitting outside, I need 2 at the coldest setting and it still feels hot.

[Jeffy]

I went out in the heat.  The temp from the vent was around 80* when it was 100* outside.  Parked at the Mall and went shopping.  By the time I got back the temp inside was around 111*.  A/C turned on and that dropped to 80*.  That was with the A/C on Max and the fan set to one below Max.  When the temp dropped to 95* I lowered the A/C to regular and the temp dropped to 70-75*.  It still seems a bit warm though.  I would have liked to have it feel like a cool glass of ice water.  At least it's working.  I can now drive it with the windows closed.

[Craigs_YJ]

Whats AC?

Do you really drive a jeep  :P

[Chief]

Jeffy:

I just bought a 97 TJ and have been experiencing some AC concerns, on my jeep, the AC works fine up until the engine warms up to operating temperture then it starts blowing warm air.  When the engine cools just a few degrees, it works then blows warm air when it again reaches operating temp.  I've re-charged the system, but it didn't help.  Any ideas on what I could check next?    :(

[Jeffy]

I'd maybe disconnect the low-pressure switch and jump the terminals in the plug.  This will allow the AC Compressor to turn on without any bearing on the pressure.  I'd start there first.

[Chief]

Jeffy:

Thanks for the advice, I'll give it a shot this weekend.  Let you know the outcome, :D

[Chief]

Jeffy:
Before I dive into my jeep and begin pulling wires, where is the low-pressure switch located?  Is there any special way I should jump the wires?

Thanks,

[Jeffy]

Well, that will depend.  Sometimes it's on the Condensor.  If it's on the condensor then it's easy to unplug and get to.

[saylor240]

ok the low pressure swicth is on the accumulator/dryer the "condensor" is the small radiator thats attached to your engine radiator ........95% of chysler a/c problems are the evaporator located under the dash ,they get small leaks and internal rescritions causing poor performance in your a/c system .you may get lucky and find small leak in hose or cap and you may have to replace your core's (located were you hook up the guage ) but the real fix is replacing the evaporator under the dash ...it will cost just about as much as new compressor or maybe more depending on where you go ...best advice .........when the evaporater  goes take the top off jeep and convert your a/c compressor to a air compressor so you can fill tires and use air tools when out WHEELIN ...........lol

[Jeffy]

Well, this was a '96/7 Blazer.  The port on the dryer leaks.  It does not leak with a gauge on there.

But when filled, the A/C would blow barely cold.  I think it might be the orifice tube/expansion valve.

Oh and this isn't on a Jeep.  So when the temps hit three digits, it gets pretty warm inside.