Outer Limits 4x4 Board

on my old fj60 it has a fast idle switch on dash seems to be plugged in ok but has no power to switch traced the wire through the firewall and has a 3 prong plug , thats not plugged to anything , seems to be a part of the a/c loom ??? reason being i cant get power to the a/c compressor , but the power is at the ac switch dragged the wire through the firewall etc checked fuses etc , a/c light on switch lights up when activated and power seems ok there . has this fast idle switch got anything to do with the a/c operation . note is running hemi 265 , so different carb ,presume thats where that plug for the fast idle went any help appreciate ,