Stupid ac compressor ?
07-17-2004, 04:57 PM
#1
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Stupid ac compressor ?
How exactly do I jump the compressor to make sure it is operative? Im trouble shooting the no workie symptoms others have run into. Its not exactly intuitive or I might have figured it out. Thanks for the help.
07-17-2004, 09:13 PM
#3
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Easiest access is ta the freeze switch, under the middle of the rain shield at the base of the windscreen. Aluminum box with two wiring connections on it. Jumper from there to the jump-start terminal and you should hear the clutch pull in. You can do this with the engine not running and avoid any risk of damage to the compressor. This assumes that there is enough freon in the system to make the presure switch close.
If you are concerend that there may not be any freon in the system, and you have tried the jumper at the freeze switch and the clutch did not pull in, you can moce downstraem, closer to the clutch. The coil lead to the clutch ties into the harness that runs across the front of the engine. There's a little connector you can pull open there, and you can apply 12V directly to the coil with no safety switches in between. Again, you can do this with the engine off, and watch/listen for the clutch to engage. If you could not get the clutch to pull in when you jumpered at the freeze switch, but it does pull in when you connect directly, it's likely that your freon has leaked out to the point where it's not safe for the compressor to run.
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The later cars (like yours and mine...) have a small undersized relay that turns cutrrent on and off to the clutch. You can diagnose with a voltmeter if you find that jumpering at the freeze switch causes the clutch to engage. Post back here if that's what you find, and we'll go from there. The relay diagnosis and a possible cure are discussed in archived rennlist posts, and at Greg Nichols' 928 tips website. Worth a look.
If you are concerend that there may not be any freon in the system, and you have tried the jumper at the freeze switch and the clutch did not pull in, you can moce downstraem, closer to the clutch. The coil lead to the clutch ties into the harness that runs across the front of the engine. There's a little connector you can pull open there, and you can apply 12V directly to the coil with no safety switches in between. Again, you can do this with the engine off, and watch/listen for the clutch to engage. If you could not get the clutch to pull in when you jumpered at the freeze switch, but it does pull in when you connect directly, it's likely that your freon has leaked out to the point where it's not safe for the compressor to run.
----
The later cars (like yours and mine...) have a small undersized relay that turns cutrrent on and off to the clutch. You can diagnose with a voltmeter if you find that jumpering at the freeze switch causes the clutch to engage. Post back here if that's what you find, and we'll go from there. The relay diagnosis and a possible cure are discussed in archived rennlist posts, and at Greg Nichols' 928 tips website. Worth a look.
07-18-2004, 10:26 AM
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Thats just the info I was looking for Dr Bob.....Ill post back with some feedback. Thanks a bunch
ok...Im trying to get the clutch to engage. Im fairly certain I have a low freon condition but just wanted to confirm.
ok...Im trying to get the clutch to engage. Im fairly certain I have a low freon condition but just wanted to confirm.
