A/C Pressure Readings Out of Whack - Need Help! - JeepForum.com
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post #1 of 5 Old 05-30-2012, 08:45 PM Thread Starter
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A/C Pressure Readings Out of Whack - Need Help!

My a/c hasn't worked for a few years (since I got the 87 XJ) and never messed with it until now. I checked the low side pressure and it showed zero. When I tried to add refrigerant the gauge needle shot into the red zone showing it was over charged.

I had heard that this can happen and to try for 30 seconds and see if gauge lowers. It didn't. So which reading is correct? How can I tell? The reading with both taken with the engine on. However, the compressor doesn't seem to be engaging, which I heard can happen when the refridge gets too low.

When I turn on the a/c at max, the pulley turns but the middle part (the compressor?) doesn't. Again, I was told that can happen with the refridge is low. I reseated the a/c relay but didn't change anything (i didn't clean the connections but I may just get a new one and try it).

Not sure how to tell if the compressor is bad or if there is another problem. I've heard of people jumping it but I'm not very good with that kind of thing. How do you do it?

I know I can take it to a shop but I'm trying not to spend the money unless I absolutely need too.

Any feedback would be appreciated.

leichte is offline  
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post #2 of 5 Old 05-30-2012, 09:43 PM
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1997 TJ Wrangler 
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Make a jumper wire and use at the high pressure switch( usually located near the dryer(accumulater). Btw, the gauge pressures don't mean anything unless you compressor clutch is engaged( the center part you referenced)
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post #3 of 5 Old 05-31-2012, 07:48 AM
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1998 XJ Cherokee 
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Yep^, but it would be the low pressure switch. Jump the pressure switch to cycle the compressor. While your watching the gauge, pressure should drop and it should need more refrigerant. If the pressure dosent drop after a few seconds of cycling your have other issues.

98 XJ lifted/Locked/Geared
My Build: http://www.jeepforum.com/forum/f177/my-98-build-1253511/
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post #4 of 5 Old 05-31-2012, 09:52 AM Thread Starter
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I know this is probably a basic question but how do I do the jumper wire. Do I run from the battery to the pressure switch? To the battery or the battery lug on the starter relay?
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post #5 of 5 Old 05-31-2012, 10:07 AM
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1997 TJ Wrangler 
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Just jump across the terminals inside the plug with the Ac switch engaged of course.if you have power here it will force your compressor to engage. If not take a simple test light and verify power at the plug and work backwards to find the issue
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a/c , air conditioner , compressor

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