How to know if the fan clutch is on or off?
There is several of these normally closed switches on the a/c and temp sensor and then there is the solenoid itself the one that gives air pressure to the fan clutch. The simple way to start is just to jump these switches to check them and hot wire the air solenoid to see if it turns on and off. This is the easiest way to eliminate these things.
How does a torque limiting fan clutch work?
A torque-limiting fan clutch reacts to engine speed. A centrifugal valve opens to allow the flow of heavy silicone fluid, locking the fan blades to the pulley. At idle and low engine speeds, this fan clutch is fully engaged, gradually disengaging as engine speed increases.
How does a thermal fan clutch work on a car?
When the fan clutch engages, it spins up greatly, increasing air flow through the radiator and over the engine. A thermal fan clutch reacts to temperature of the air rushing over it from the radiator. As the radiator heats up, the air passing through it also heats up.
How does a fan solenoid work in a clutch?
Most fan solenoids are controlled by ECM ground. They are inline with the ECM that turns on a transistor to complete the circuit to ground. Because they are designed as failsafe, the ground circuit is completed when the fan is not needed. Meaning, the solenoid is grounded, allowing air flow to the clutch to keep the fan off.
How does the fan clutch work on a snowplough?
But your truck has an Electro-Viscous Fan Clutch and the speed is controlled by the PCM. I believe that the PCM monitors the oil temperature and A/C Unit among other inputs to regulate the speed. Also if you have a snowplough PTO package, this also affect the PCM fan speed output (PCM Programming is different).
Why does the engine fan keep coming on and off?
The engine fan will only stay on for a few reasons. Mosf of the time the fan clutch solenoid is bad. It is an electric solenoid that turns the fan on and off. You can find it by following the air line that comes from the fan clutch hub. In you case, it may be the A/C high or low pressure switch since you are getting an A/C trouble code.
Is there a fan in the engine compartment?
No, it is in the engine compartment, it is a sensor. A bad fan clutch solenoid is usually the first thing to look for but could be several things.