hey_obie Posted December 17, 2011 Report Share Posted December 17, 2011 It was time to replace the belts on my 89. I fired up the engine to watch things work and noticed the fans kicked on. It was 40 degrees out and I didn't think the engine was that warm. They kicked off after a minute or so. A minute or two later, they kicked on again and I noticed that the A/C compressor was kicking in. I had the cabin temperature set to 77 on Auto. The engine is not hot enough to call for the fans. For some reason, the system is calling for A/C. Any thoughts? I think the cabin sensor maybe the culprit because if I have it set to 77, the cabin temperature doesn't get there. Anyone had this problem? Thanks Link to comment Share on other sites More sharing options...
Skullzaflare Posted December 17, 2011 Report Share Posted December 17, 2011 it may be turning defroster on, is it blowing at the windshield? Link to comment Share on other sites More sharing options...
hey_obie Posted December 17, 2011 Author Report Share Posted December 17, 2011 (edited) The defrost light is on until the car warms up (as it should). I didn't know the a/c went on automatically under defrost. Anyway, the A/C compressor still kicks in turning the fans on even though the defrost light is off. The fans run for a very short time. About 10 seconds and then shuts off for a couple minutes. Strange. Nothing worth losing sleep over, but I don't think it is right. Something is making it kick on. Edited December 18, 2011 by hey_obie Link to comment Share on other sites More sharing options...
vbrad511 Posted December 18, 2011 Report Share Posted December 18, 2011 My compressor kicks on anytime I turn the heat on to anything below the max setting. Doesn't matter where I set the vents. Link to comment Share on other sites More sharing options...
hey_obie Posted December 18, 2011 Author Report Share Posted December 18, 2011 The only real problem with it is that I don't want to have the compressor kick in when I am racing a Mustang or Porsche, . Link to comment Share on other sites More sharing options...
Indiana Posted December 18, 2011 Report Share Posted December 18, 2011 The compressor comes on when in the defrost mode on any car unless its a cheap one that uses a manual a/c compressor switch or that has no a/c. The compressor comes on to DRY OUT the air. Say you are driving in cool weather, you have 4 people in the car and its starts to rain. Unless the compressor comes on all you'll have is fogged up windows you can't see out of. In winter you can get in your car and breathe a few minutes and fog up the windows, if you have to wait 30 minutes for the car to warm up and heat up the air in the car to defog the glass that's what people in non a/c cars did in the old days. You can try rainX anti fog on your windows it does work. If you have ditched the two terminal temp. gauge sending unit for the lessor price single one that will cause the fan to have a higher speed and can switch and blow that cold air in your face when its cold. Link to comment Share on other sites More sharing options...
hey_obie Posted December 18, 2011 Author Report Share Posted December 18, 2011 I have two quests and have worked on them for 7-8 years. Never noticed the compressor was kicking in. I always thought it was the radiator sensors turning the fans on to cool the engine. Thank you Indiana for the explanation. Glad it is all normal. Will sleep like a baby tonight. Link to comment Share on other sites More sharing options...
ucw458 Posted December 18, 2011 Report Share Posted December 18, 2011 When the system is on press the economy button twice. That's sortof a manual override that shuts off the AC compressor permenantly. To get AC again just press auto. I use that mode all the time when I just want fresh air without AC. You will still get heat if you turn the temp up. Link to comment Share on other sites More sharing options...
hey_obie Posted December 19, 2011 Author Report Share Posted December 19, 2011 ucw, I guess that one is in the manual. I'll check. Thanks Link to comment Share on other sites More sharing options...
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