You're confusing the pressure switch W0133-1628267 with the temperature switch W0133-1626582. The first is for low or excessive pressure (30psi low, 435psi high), which cuts out the compressor, while the other activates at normal operating pressure to turn the aux fan on. It does not wait until the pressure is "excessive" to activate; that would result in a very short compressor life and overall decreased efficiency. The lower the condenser temp/pressure, the cooler the compressor and the lower/cooler the evaporator temperatures (to a point).

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A.S.E Tech A1,A6,A7,A8 & MVAC 609 + EPA 608

Unless stated otherwise, any question I ask is about my greymarket 1985 380SEL.