Engine fan intermittent won't turn off

[Trey7981]

The fan cluth is good. The problem is at the solenoid air valve. Can some one tell me what activates the solenoid? And what volts and amps should be at the plug? Trying to test if it's the solenoid or a bigger problem.

[Rawze]

check on insite software to see if it is being commanded on or off when it is acting up. Otherwise you are just chasing your tail on it.

most common issue with intermittent fan clutch is actually the AC pressure switch. If it reads 0 or too high.. then the engine fan comes on. This means that intermittent connection, corrosion in the plug, or a bad sensor will cause your symptoms.

[Trey7981]

Last night when I was checking the solenoid. I did notice my ac clutch was engaged even though I had the heat on.

[SquareOne]

(02-16-2023 )Trey7981 Wrote:  Last night when I was checking the solenoid. I did notice my ac clutch was engaged even though I had the heat on.

This is normal. Compressor will cycle in order to dry the air out otherwise you will create plenty of moisture from introducing heat alone (i.e. fogged windows) in the cab.

Typically you notice this when you run the defrost option. The default on the defrost selection will engage the a/c compressor in order to dehumidify the air and assist in removing the fog from glass.