Ford 1996 Aspire Manual page 78

Sometimes you may notice slight engine surging
if you have the air conditioner on. This is
normal, as the system is designed to cycle the
compressor on and off to maintain desired
cooling. The reduced compressor operation
should benefit fuel economy.
On some vehicles with air conditioning,
wide-open throttle acceleration will temporarily
cut off the air conditioning.
Since the air conditioner removes a lot of
moisture from the air during operation, it is
normal for water to drip on the pavement under
the air conditioner drain after you have stopped
the vehicle.
Engine Idle Speed Control System
Genuine Ford air conditioning (either
factory-installed or dealer-installed) has an
engine idle speed control system that
compensates for engine speed loss that may
occur when the air conditioning compressor is
running. This idle speed control holds the engine
idle essentially constant, regardless of whether
the air conditioning system is on or off.
If an aftermarket air conditioner is installed, an
engine idle speed control system must be
installed. Otherwise, the engine may not operate
satisfactorily at idle speed and low engine speed,
or the engine may stall.
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