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Old 08-14-2006, 08:35 AM
mbdoc mbdoc is offline
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
The RPM shouldn't increase but remain the same as with the a/c off.

The CIS control unit controls the idle circuit.

The aux fan should come on when the engine reaches 107C or when the a/c system pressure reaches 16bar...about 240psi on the high side.
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