Read the "Mad Mole" link provided by another member on your other post. Some of the info is wrong IMO. Pressure switch contact activates hi-speed fan operation only, not idle.
PCM continually adjusts engine controls to keep idle within spec., a/c on loads engine, rpm drops PCM compensates (presumably using IAC and injector pulsing) to maintain rpm within I4 idle spec(atx 800+/-50, mtx 880+/-50).
If rpm drop by 200 PCM will shut a/c off as it attempts to avoid stalling.
98 Mystique LS v6 atx 110,000km
97 Contour LX v6 atx 125,000km
stock CD on LS, cass on LX
spoiler, tinted windows on LS only
4 wheel discs on LX only
All other available options on both
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