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Looking for quick advice on A/C ( I USED SEARCH)

willsmysticcobra

willsmysticcobra

NAXJA Forum User
Location
Lake Zurich IL
Hey guys, so its been 94 here in chicago and I need air in the ole DD 1999 xj 4.0l. I bought a 40 dollar A/C recharge kit to which it read 12 psi on my low side. Problem is I do not hear the A/C clutch engaging when I put it to max A/C with 48 psi just loaded in to the low side port. Do I gamble and pony over $170 ish to rock auto and get a new A/C COMPRESSOR or should I just take it in to a licensed pro? All fuses and relays look ok and to be intact. I pray its not the evaporator under the dash . Thanks guys :wave1::thumbup:
 
Unless you have pressure in the system the low side switch will prevent the clutch from engaging.

Considering all the legalities that go into working on refrigerant systems now days, it may be best to have the Dealer look at it and give you a quote before spending anymore money on refrigerant.
 
ya I agree... although I found an interesting update.... Upon re-looking over the system, the original owner looks like zip tied the connector from the a/c compressor to a main thick harness... meaning it was just ziptied and not connected... upon connecting, the aux fan turned on, but still no clutch kick. so now I have 12v going to the compressor, all relays/ fuses look good and I have 55 psi sitting on the low side. Is there a way to jump the clutch does anyone know?
 
theres an electrical lead coming off the compressor, its got a bullet quick disconnect on it... tap that to +12, you should hear a loud combinaton of a clink and a clunk. you can also see the clutch slide in or out under the pulley.
 
the compressor has to be shot and the previous owner just didn't disclose it. The bullet connector and the other connector that completes the circuit were tied off together. Took a wire from the battery to the bullet connector... nothing. Tested the switch on the top of the evap, works fine ( when unplugged, the aux fan goes off) so it leads me to believe it has to be that darn compressor.
 
^ yes I believe so. I mean when I first popped the hood, the bullet connector, and other second harness were both ziptied together. Upon connecting both, the aux fan shot on which was a good sign. I than pulled the switch off of the air accumulator, the aux fan turned off, thus interrupting the circuit.

When I had a piece of scrap wire, I touched the positive from the battery to the single lead in the bullet connector with the car running etc... nothing :(
 
Does the compressor in the 99 still have that shim in the clutch? the clutch material can wear and the shim will not allow it to engage.

taking out the shim in my '92 was the cheapest AC fix I ever had.

you can also use a dvm to check the clutch coil

If the compressor itself was bad the clutch would engage it and you would know it was bad from the god awful noises that would come out.

It sounds to me like the compressor is never being engaged. I believe the pulley clutch and the coil are both replaceable and you don't have to open up the system. (but don't quote me on that.)
 
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FYI - There's an easier way to jump the compressor if you're low on freon and need it to come on to add more - jump the Low Pressure Cutoff Switch (paper clip works great here). That should fool it into coming on.

Now if you've still got other main wiring issues for the compressor, this won't do you any good...
 
Sadly I have 45 psi waiting on the low side to go somewhere, so low freon is not the issue I dont believe.
 
45 PSI static pressure, right? Seeing as how the compressor isnt running? If that's the case i'd say you're still low, or possibly right on the edge of where the low pressure switch activates.
 
FYI - A/C system - outside ambient air temps vs. guage pressures at the low pressure charge port:

@70* F = 26-35 psi
@80* F = 32-41 psi
@90* F = 38-47 psi
@100* F = 44-53 psi

Edit: These pressures are with a fully serviced and operational A/C system
 
I still think you should make sure the clutch system is working. If it's not, nothing else you do will matter. You can jump power and ground to the clutch coil - there is a procedure in the FSM, section 24 - and make sure it engages. NO other factor can stop it from engaging if the coil and clutch are good.

If it makes a big Click but does not engage the compressor, the coil is good but the clutch is worn down and a shim or 2 may need to be removed from the shaft behind the clutch plate.

If there is no click when you jumper power and ground to the coil, it is bad and nothing else you can do will make the compressor engage.

(when I say bad, it could also mean the power or ground connections to the coil are bad or broken.)
 
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willsmysticcobra said:
ya... hmmm. I had it at 55 psi and it was a tad in the red on the autozone gauge
Click to expand...

Those types of gauges that come on the "artic freeze" cans are notorious for being wrong. Ideally you need to have a manifold gauge set on it so that you can see both low and high side pressures.

I've got one from Harbor Freight that I gave like $40 for if I remember correctly. Works very well for the AC work i've done so far. They go on sale frequently as well.

Edit: On sale now actually for $40

http://www.harborfreight.com/a-c-manifold-gauge-set-92649.html
 
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