Bronco II AC compressor does not turn off

[Broncopower33]

Have an 1989 bronco 2, AC works great, just noticed compressor/ cutch doesn’t turn off when in the off position. Wondering if anyone has had the problem or a fix.

 

[franklin2]

If you wired in a electric fan, that will cause that. You need a diode in the wire to act as a check valve for the power.

 

[RonD]

AC compressor is also ON when Defrost is selected, that's to dry the air in the cab, so make sure Defrost is not selected, this over rides the AC on/off

There is a WOT(wide open throttle) relay that may be the problem
In the engine bay there are 3 main relays
Fuel pump, Green base(plug-in)
EEC, Brown base
WOT, Black base

Unplug WOT relay and see if compressor shuts off, it should
Check base for corrosion

The AC button/switch on the dash sends 12volt thru the AC pressure switch(s) and then to the WOT relay which then sends it to the compressor clutch

If there is a 12volt short at the AC button or anywhere along the pathway then Clutch will stay engaged


Ignition switch---cab fuse box--------AC button-----pressure switch-------WOT relay-------AC Clutch


The WOT relay passes the 12volts to clutch when its OFF, not on, computer turns on this relay, CUTTING POWER to AC clutch, when driver presses gas pedal to the floor(WOT) to give driver all available power for passing or ??