sira idle up/vacuum switch niyan or may singaw ang air hose. yun vacuum switch ma activate ng voltage from your aircon compressor. yun air para sa vacuum switch mo galing sa intake manifold. then pag on yun (aircon on) may another thingie that pulls (or pushes) the throttle para tumaas idle mo when activated yun compressor. dapat idle without aircon around 700 rpm, pag on aircon (compressor) 700-750rpm.