A/C Troubles

[Jeepster19]

I noticed recently that on long trips,about 2 hours or more that my a/c isn't blowing as cold as it was when I first left,starting with the a/c on max cool.As the interior started cooling down&getting colder,I backed off on the blower motor one notch.As the trip progressed,I backed off one more notch and left it at that.Interior was at a decent 50 degrees,so I left it there.As the trip got into the last 45 minutes I noticed the temperature rising,60 degrees to be exact.So I turned the a/c back up to max cool on the blower switch for awhile and nothing changed,still at 60-62 degrees roughly.I don't know what is going on,the entire a/c system has been replaced,just doesn't make sense!It seems to work great on short trips but falls short on long trips.Can anyone tell me what might be going on?Almost forgot,I had condensation dripping on the interior also.Temp outside was in the high 90's with high humidity in s.c.:confused:

[4.3LXJ]

First guess is icing up. Try this next time it happens. Turn the selector to vent and just use the fan. Should thaw it out in about ten minutes or so. Then turn it back to AC. If it operates normally, it is just too cold and freezing the condensation. A small shot of R134a will fix it.

[Jeepster19]

Ill give that a try,I guess it can't hurt.I have to go buy a new set of gauges to check the low&high side.I also noticed that when the a/c stopped blowing cold I was getting a lot of condensation drip in the interior,that can't be normal.Seems like it's draining outside,maybe the drain is partially clogged.:confused:

[nickxj94]

Ill give that a try,I guess it can't hurt.I have to go buy a new set of gauges to check the low&high side.I also noticed that when the a/c stopped blowing cold I was getting a lot of condensation drip in the interior,that can't be normal.Seems like it's draining outside,maybe the drain is partially clogged.:confused:

Could be mine was I stuck a pick up the tube and pulled a few leaves out and it drained about a half gallon of water out. Now I know why the pass side floor is rotted out and why the carpet stayed wet

[Jeepster19]

Mine had light surface rust starting on the passenger side.Good thing I checked under the carpet or it might have rotted out.I wasn't so lucky in the rear cargo area.The RH side down in the crevice of the qtr panel where the rubber plug is,has rotted out.Very disappointing because my Xj is super clean otherwise.Its hidden for right now because of the plastic bumper extensions but I'm going to have to get new metal welded in at some point&time.

[nickxj94]

Mine had light surface rust starting on the passenger side.Good thing I checked under the carpet or it might have rotted out.I wasn't so lucky in the rear cargo area.The RH side down in the crevice of the qtr panel where the rubber plug is,has rotted out.Very disappointing because my Xj is super clean otherwise.Its hidden for right now because of the plastic bumper extensions but I'm going to have to get new metal welded in at some point&time.

My 94 is a rust bucket lol I replaced everything but the back cargo area its to far gone I'm just going to drive it till it falls apart :D then by me a 97 to 99 next year

[Jeepster19]

I found that there is a T.S.B.,technical service bulletin on 97-99 Xj's&97-99 Tj's.A/C evaporator freezing up.The low pressure switch seems to be the problem.Your Vehicle: 1998 Jeep Truck Cherokee 4WD L6-4.0L VIN S

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Vehicle*»*Technical Service Bulletins*»*Customer Interest*»*A/C Evaporator - Freeze Up *
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* A/C Evaporator - Freeze Up *
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Number: 24-13-99
Group: Heating & A/C
Date: July 2, 1999
SUBJECT:
A/C Evaporator Freeze Up
OVERVIEW:
This bulletin involves installing a revised low pressure cycling switch.
MODELS:
1997 - 1999 (TJ) Wrangler
1997 - 1999 (XJ) Cherokee
SYMPTOM/CONDITION:
Intermittent low A/C output due to reduced airflow through the evaporator or excessive condensation draining from the vehicle after the vehicle has been turned off due to evaporator freeze up. The system will operate normally in most conditions. The condition will only occur after extended periods of driving with the A/C system operating. The system will return to normal operation after the NC system has been turned off long enough for the ice on the evaporator to melt.
DIAGNOSIS:
If customers complain of this condition and no other NC system problems are found, perform the Repair Procedure.
PARTS REQUIRED:
1 05015871AA Low Pressure Cycling Switch (1997 Models)
1 05015872AA Low Pressure Cycling Switch (1998 - 1999 Models)
REPAIR PROCEDURE:
THIS REPAIR IS COMPATIBLE WITH DAIMLERCHRYSLER'S MOBILE SERVICE PROGRAM AND DOES NOT REQUIRE HOISTS OR OTHER FULL SERVICE FACILITY SPECIAL EQUIPMENT.
1. Disconnect and isolate the negative battery cable.
2. Disconnect the low-pressure cycling switch connector from the low pressure cycling switch located on accumulator.
3. Remove the switch from the accumulator and remove the 0-ring.
4. Lubricate the 0-ring with refrigerant oil and transfer it to the new switch. Install the new switch. The switch should be hand tightened to the accumulator fitting.
5. Connect the harness to the switch.
6. Connect the negative battery cable.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 24-35-35-90 0.2 Hrs.
FAILURE CODE: P8 - New Part
I just got my A/C gauges in so I'm going to check it out tomorrow,hopefully.

[Jeepster19]

Checked the old low pressure switch,it turned out to be bad.Installed a new one,hooked up the gauges.Started it up&waited for the compressor to kick in,this took about 20-30 seconds.After that,the compressor started cycling frequently.Which tells me it is low on freon.Added freon&got a reading of 30 on the low side&225 on the high side with a ambient temperature of 85 degrees roughly.Took it down the road and got a temp out of the center vent of 53 to 55 degrees.The temp should be much lower,I think.Somewhere in the 40 to 45 degree area.Can someone tell me if I am doing something wrong,I am getting frustrated.:bang:

[4.3LXJ]

Did you get any air in the system?

[Jeepster19]

There's a possibility. Would that cause it not to cool correctly?

[4.3LXJ]

Yes, air in the system will not let it operate like it should. Refrigerant and oil is the only things you can have in the system

[Jeepster19]

I guess I should start from scratch and evacuate the system& then pull a vacum.If all checks well on the vacum procedure I'll proceed to fill it back up again.How do you keep from getting air in the system?

[4.3LXJ]

You use a set of gauges, vacuum through them. They will tell you when you are there. Then close them off and see if it holds. Then charge through the gauges. Use the yellow hose to evacuate and charge.

[Jeepster19]

Thanks,I'll update you tomorrow.:cool:

[Jeepster19]

Finally getting around to working on the a/c system.Both high&low side valve cores are replaced,now it's time to vacum it down to see if I have any leaks.http://i573.photobucket.com/albums/ss179/jeepster19/6d115135ecf24cd92b60727beae3deac.jpg

[4.3LXJ]

When you charge it, turn the can upside down to charge properly

[Jeepster19]

You use a set of gauges, vacuum through them. They will tell you when you are there. Then close them off and see if it holds. Then charge through the gauges. Use the yellow hose to evacuate and charge.

Got the a/c system free of leaks&all charged up.I have a high side reading of 235 and a low side reading of 28 with an ambient temperature of 81 degrees.The center vent is 45 degrees at idle,that should do it!Thanks for all your help,I really appreciate it.:thumbsup::D:D:D

[Mudderoy]

Finally getting around to working on the a/c system.Both high&low side valve cores are replaced,now it's time to vacum it down to see if I have any leaks.http://i573.photobucket.com/albums/ss179/jeepster19/6d115135ecf24cd92b60727beae3deac.jpg

Both the 99 and 98 are leaking like a sieve, and I cannot find the leak.

Matt pulled vacuum on both systems for 45 minutes and they held just fine. I think I'm getting ready to learn a lot about A/C systems. I have a gauge set now, I just need to get a vacuum pump.

[4.3LXJ]

Tony, shoot some dye into them and get yourself a UV penlight. Then turn off the lights and search for the yellow in the dark. Also look for the telltale oil around fittings and such.

[Mudderoy]

Tony, shoot some dye into them and get yourself a UV penlight. Then turn off the lights and search for the yellow in the dark. Also look for the telltale oil around fittings and such.

Done it! I even have an electronic sniffer.... :bang:

[4.3LXJ]

Hate to say this, but then it might be in the evap core

[Mudderoy]

Hate to say this, but then it might be in the evap core

Yep, I have a new one waiting to go it, but no smells and the electronic nose doesn't get any hits from the vents...