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  #1  
Old 06-08-2004, 08:35 AM
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Join Date: May 2004
Location: RI
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1992 300E a/c not working

Just bought car and air wasn't working. So refrigeration guy at work looked at it, put some nitrogen in to pressure test, it held, so he charged it up. It worked nice for a couple of weeks but it just stopped working, not blowing a hint of cold at all.

He's on vacation so will be awhile till hes back. There is pressure but I dont have a gauge to check the number.

Looked at compressor and it goes to engage clutch for a second but wont hold, it disengages, then goes to engage 30 secs to a min later, but only holds for that 1/2 sec then disengages.

The belt looks tight and does not look oily so I dont think its slipping.

Any thoughts guys?

Thanks, Jeff

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  #2  
Old 06-09-2004, 08:40 AM
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Can any of the A/C experts out there point me where to check next ?

Thanks, Jeff
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  #3  
Old 06-09-2004, 12:56 PM
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Location: Nashville, TN
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You may have a bad clutch.

OR

A leak, and the compressor disengages due to low pressure.
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  #4  
Old 06-09-2004, 03:23 PM
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Thanks brookspw,

The guy may swing in to work tomorrow so will be able to put a gauge to see how high pressure is. I'll check that first.

Thanks, Jeff
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  #5  
Old 06-09-2004, 03:43 PM
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The compressor will do that when it's low on refrigerant. A lot of good a/c techs inject dye into the system anytime they service the system. It helps them locate the problem on a return visit. Hopefully your tech used this (UV) dye. Next time you visit him he'll look for leaks with a black light.
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  #6  
Old 06-10-2004, 01:07 PM
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Well, He checked pressure and its dropped enough so compressor wont kick in. He says its a slow leak. He doesnt have any uv dye since cars he only helps out people he knows and doesnt need it for commercial. He gave me some solution that bubbles up to spray over all the fittings. I'll try this first before I investigate buying a uv kit or having an a/c place find leak but dont really know of any shops that specialize in a/c. Maybe Ill get lucky and a fitting is weeping.

Dreading the worse here, if I do get to the UV stage, to check the evaporator in the dash, will I be able to see anything w/o ripping the dash apart?

Thanks, Jeff
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  #7  
Old 06-10-2004, 01:33 PM
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As far as solutions go, I simply use water with soap mixed in it to look for leaks.

To diagnose the evaporator in situ, either of two methods may be used. One is to use an electronic sniffer made for sniffing refrigerant. I heard they work well. The other is to inject UV dye into the system, charge the system enough to get some cooling action, then check the condensate dripping from the evaporator box with a black light for presence of dye.

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