02 Dodge Grand Caravan ES A/C problem

I have a 2002 GC ES with an A/C problem. The temperature here in Iowa got up to 85 and the A/C will not engage. I have checked the fuses, and the relay, all are good. I had no problems with this last summer.
Also, there is a terrible knocking in the motor (3.8l V6 with 42k) at idle and crusing speeds. I tried Lucas oil and 10W30, but it only worked for a week.
Thanks in advance for your help.
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Assuming the compressor is in good shape and not causing the knocking noise you need to check for a proper charge of freon in the system, if it is low the low pressure cutout switch will not allow the compressor to turn on.
Glenn Beasley Chrysler Tech
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Thanks for the tip. I recharged it with R134A and it works like a charm.
Scott T. Indresano
maxpower wrote:

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Any idea what could be causing the knocking sound? Lifters, valves?
Scott T. Indresano wrote:

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and
on.
Yup and yup....but without hearing the noise I cant tell you what it is.
--
Glenn Beasley
Chrysler Tech
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