96 Cherokee Sport 4.0HO A/C not really keeping it cold...

a/c does not seem to be quite doing it;s job... it's getting cold but it does not seem to keep up on a 85F or warmer day... even if on the highway... if I put my hands right up to the vent it feels cold... it just really does not feel cold by the time it hits my body...

outside temp is 77F



static pressures

Low side 92psi

high side 98psi



idle pressures

low side 22-35psi (flutters a bit)

high side 175-180psi



2000-2500rpm

low side 10-15psi

high side 190psi


ideas?

I'm sure theres a better technical explanation but i've never had an A/C on my three XJs that worked worth a snot. I'm more of a windows down kinda guy so i didn't mess with them. Mabye someone will chime in with a good explanation.
As i understand it, these engines are crammed into such a small compartment and theres so much heat under the hood the A/c s just cant keep up. But thats just word on the street.

Wallyman said:

I'm sure theres a better technical explanation but i've never had an A/C on my three XJs that worked worth a snot. I'm more of a windows down kinda guy so i didn't mess with them. Mabye someone will chime in with a good explanation.
As i understand it, these engines are crammed into such a small compartment and theres so much heat under the hood the A/c s just cant keep up. But thats just word on the street.

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Mine freezes my a$$ off but I live in the northwest. It's still like 58 degrees up here!
Maybe your fan isn't blowing hard enough? You said it's cold at vent but not on you.

Wallyman said:

As i understand it, these engines are crammed into such a small compartment and theres so much heat under the hood the A/c s just cant keep up. But thats just word on the street.

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if that was the case they would not even bother putting an A/C in the Jeep... and honestly there is plenty of room in there...

turns out that when it starts blowing warmer air, it's because the compressor has shut off...

ideas?

The only info I have for you is the blend door, just make sure its shut all the way. If you have an FSM, you may find some spec ranges for what you've got. (ie line pressures.) My friends 99 will freeze you out when its on full, works great.. (yeah I know its not a 96.)

Check you condenser to make sure its not full of dead dragonflies, and the fins are straight.

ericfx1984 said:

turns out that when it starts blowing warmer air, it's because the compressor has shut off...

ideas?

Click to expand...

Sorry just read that. Gotta figure out why the compressors shutting off. Once again, FSM will give you average cycle time for the compressor. MY guess, line pressure dropping somehow, pressure sensor turning off compressor.

Also check relay conditions (swap).

Somebody here will point you in a better direction.

I think I found the problem...

even though I am getting 90psi or so static the compressor would not kick on...

so I tapped into the + lead going to the A/C clutch... it had power... then I tested it a little closer to the compressor... NOTHING!

I thought that the probe might not have made contact so I pushed it a little harder... then suddenly the compressor CAME ALIVE!!!

turns out I have a short... the battery is rubbing against the wires going to the compressor...

it ran nice and cold....

maybe tomorrow I will fix it