Compressor Clutch Service and Repair
Air conditioning compressor clutches work in a similar way to the clutches in an automatic transmission. The clutches are modulated by using pressurized hydraulic fluid, which increase and decrease in pressure depending upon the application. When the pressure decreases, springs in the housing cause the clutch to release, whereupon splines lock the housing and the gears together. Your air conditioner’s compressor clutch is electromagnetic, which means that it can engage or disengage while the engine is still running. Whenever there is a current flowing through the clutch (i.e. when you turn on your air conditioning), the clutch engages and remains engaged. Once you turn off the air conditioner, the current stops and the clutch automatically disengages. Most air conditioning systems also come equipped with a belt driven cooling fan that uses a thermostatically controlled viscous clutch. This clutch actually uses the temperature of the fluid inside the clutch to decide when the fan’s clutch needs to be engaged.
