Rough idle with ac on

Nov 16, 2003 2 Replies

Got a 95 Blazer. Is it normal for the engine to idle a little rough with the ac switched on?



RPM goes constantly up or down about 100 each time the ac makes a loud click with a couple of seconds distance. Has been this way since i bought the truck and the previous owner tells me it has been this way since he got it 4 years ago.


Rough idle with ac on Group: alt.autos.4x4.chevy-trucks Date: Sun, Nov 16, 2003, 7:16pm (CST+6) From: snipped-for-privacy@netcom.no (VLH) Got a 95 Blazer. Is it normal for the engine to idle a little rough with the ac switched on? RPM goes constantly up or down about 100 each time the ac makes a loud click with a couple of seconds distance. Has been this way since i bought the truck and the previous owner tells me it has been this way since he got it 4 years ago.

sounds like you compressor is drawing to much voltage when it kicks on....The Click is our compressor kicking off and on....

It is the compressor engaging and disengaging. Each time it does this it adds (or reduces) the drag on the motor. When it is not engaged, the pull spins freely, when it is engaged, it is using power from the motor to accomplish it's task. You don't notice it on other things because they all run constantly (waterpump, alternator etc.) So unlike what Steve would lead you to believe, this is normal. My 88 S-10 does the exact same thing, has done so for the 10 years I have owned it. Every other S-10 I have been in has also exhibited this exact same thing.

Big Chris

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