GMT 800 & Older GM General Discussion 2006 & Older Trucks | General Discussion

AC compressor not engaging?

Old May 9, 2008 | 05:44 PM
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Default AC compressor not engaging?

What can I check? The AC fuse under the hood is good. The belt is good. The pressure is good. What else is there?

Can the HPTuners scanner help?

Please help, I went out to pick up some parts and was soaking with sweat by the time I got home
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Old May 9, 2008 | 06:11 PM
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It is most likely the cycle switch at the dryer. You might try tapping on it slightly and it might start to work. It's a simple and cheap fix to replace
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Old May 9, 2008 | 06:14 PM
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Thanks, I'll try that.

But where is it?
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Old May 9, 2008 | 09:05 PM
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What is the pressure, exactly? There is a minimum to make the low pressure switch.
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Old May 9, 2008 | 09:57 PM
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the low pressure cycling switch is located on the dryer/accumulator, the big roundish aluminum cylinder with a few hoses goin to it on the passengers side firewall. You can either tap on the switch lightly with a wrench or you can jump the connector with a paper-clip if your careful to not spread the terminals out...but as stated before it has to see at least 30ish PSI on the low side of the system to operate if the switch is good anyways
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Old Jun 4, 2008 | 05:24 PM
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I replaced the valve core and filled it to spec and it wouldn't work unless I jumped the terminals. When I jiggle the switch, it tries to engage, but only turns a couple times before disengaging. Is the switch bad? Do I have to discharge the refrigerant to replace the switch? Thanks.
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Old Jun 7, 2008 | 04:34 PM
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BUMP!! Should I replace the switch, or could I just have too much oil? Do I have to drain the refrigerant to replace the switch?
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Old Aug 10, 2008 | 04:56 PM
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Don't mean to jack a thread.. Figured I'd ask you guys before I start a new thread.

But I also have an A/C problem.. My 1st and 2nd blower speeds don't work. The 3rd & 4th work fine. Any suggestions.

I tried searching and could not find anything.
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Old Aug 11, 2008 | 11:50 AM
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Originally Posted by rclnc
Don't mean to jack a thread.. Figured I'd ask you guys before I start a new thread.

But I also have an A/C problem.. My 1st and 2nd blower speeds don't work. The 3rd & 4th work fine. Any suggestions.

I tried searching and could not find anything.
My guess would be that the blower resistor is burnt
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Old Aug 11, 2008 | 09:57 PM
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Originally Posted by budhayes3
My guess would be that the blower resistor is burnt

Good deal appreciate the tip.. will look into it.
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