A/C Compressor Not Cycling
#1
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Hi all, I have a couple of questions with my 97 SSE (with electronic climate control):
I hit my AC button last Saturday and got no cold air. Last night I was working on it and I found a lot of usefull information here in this forum but not enough to correct my problem yet. Comressor is free, R134a is at about 35# (according to my fill kit that is ok) but the compressor will not cycle. How do you jump the pressure switch? There are 3 wires: blk, red and tan. I swapped the relay and fuse in the maxi fuse center and still nothing. I also tried tapping on the compressor clutch. Any other things to check?
I hit my AC button last Saturday and got no cold air. Last night I was working on it and I found a lot of usefull information here in this forum but not enough to correct my problem yet. Comressor is free, R134a is at about 35# (according to my fill kit that is ok) but the compressor will not cycle. How do you jump the pressure switch? There are 3 wires: blk, red and tan. I swapped the relay and fuse in the maxi fuse center and still nothing. I also tried tapping on the compressor clutch. Any other things to check?
#2
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Bob, I'm going to have to do a little research on this tonight before I can give you an intelligent answer. Maybe before then, someone else will pipe up.
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If the compressor won't come on at all, your pressure reading is invalid. I'd have a can of r134 ready (maybe 2), and figure out how to jump the switch. I haven't looked at my Bonnie, but I've never seen one with more than 2 wires.
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The switch I am looking at is the one right behind one of the cooling fans and right below the exhaust manifold. There are definetely 3 wires. Maybe I am looking at the wrong thing?????
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Don't jump it...I think you might not have the right pressure yet. I remember looking it up last year and finding it was quite different than the "expected" on kits.
Lash..do you have your manual handy to check the required pressure?
Lash..do you have your manual handy to check the required pressure?
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I believe at 35 PSI the compressor should cycle on and off frequently... But againg it may require more pressure... The Low sid may start out at 90-100 Psi, as soon at the compressor turns on that pressure should fall to the acceptable range...
I gave mine a shot yesterday as it was cycling on and off in hot weather... I noticed it was low, A charge resolved that problem...
Now for you guys with the ECC how does the system work?
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I gave mine a shot yesterday as it was cycling on and off in hot weather... I noticed it was low, A charge resolved that problem...
Now for you guys with the ECC how does the system work?
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Originally Posted by BillBoost37
Don't jump it...I think you might not have the right pressure yet. I remember looking it up last year and finding it was quite different than the "expected" on kits.
Lash..do you have your manual handy to check the required pressure?
Lash..do you have your manual handy to check the required pressure?
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i'll take a look at it tonight and try to help a little.
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I know in your car the compressor shouldn't cycle. It'* variable displacement and will only pump less instead of cycling the clutch on and off. You could very well be low on R-134a. The only way to tell is to have the system completely evacuated and recharged with the correct amount of freon to know for sure that it'* charged properly. Plus, the accuracy of your gauge is questionable, and even 10 psi is a make or break differeance in A/C systems.
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If yours is like my '95, or older models, the low pressure switch is on the accumulator, up against the firewall. I have jumped that to check the function of the compressor clutch when the charge was too low to allow the compressor to kick in. I would not mess with the switch on the compressor, I believe that will be the high pressure switch.
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I just went out and pulled that maxi fuse / relay cover off again so I could clearly view the accumulator. There are no switches of any kind around it. The one that is behind the left cooling fan ,(standing in front of the car), with 3 wires, is in the line coming out of the high pressure side of the compressor. There is about 2 inches of line, the switch, a little expansion tank and the the line that runs into the condensor. Last night I pulled off the connector at the compressor clutch to see if I had any voltage there......and I do not. I have seen other posts talking about the pcm not commanding the AC on. What does this mean? If I have my system scanned will it tell me anything about the AC? I have had no SES light on.