D 150 Ramcharger V8-360 5.9L (1989)
Compressor Clutch Relay: Description and Operation
The A/C clutch relay is connected to the A/C damped pressure switch, the A/C switch and the A/C fan relay. The relay is in the On position during
normal engine operation, but is closed when the SMEC senses low idle speeds or wide open throttle conditions, preventing A/C clutch engagement.