Fan clutch don't come on

Did u what happens when u turn ignition off so u hear the solenoid release the air or can u spin fan with ignition off

 

What temp does you're truck get up to fan is supposed to kick on at 210f also u can try to turn on with ac system of fully charged when high side pressure gets to 300 psi fan will come on there is nothing really that keep the fan off If its working with ignition that means that all the wiring is good because you're solenoid gets 12 v to shut off fan not turn on when it's on there is no power at solenoid

 

Not sure if it's the same on freightliner but on my old Volvo there was 1 plug that I could unplug and it would lock the fan on. If you can find it and do that it will tell you at least which side of the system the problem is. If it works somehow it's not getting the electrical signal it needs. If that doesn't work it's not getting the air to operate it. Unfortunately for me when my fan went it was the clutch itself so I couldn't even lock it on. Had to have a mechanic come and shim it so I could drive home and get it fixed.

 

What is your voltage at solenoid?

 

If that true for the 2004 FL M2 106, no 12v to solenoid when fan is running, only 12v to solenoid when fan should stop running? My '04 FL M2 106 freely spins with engine on or off, and fan only comes on when over 210f, I want fan ON much earlier so I'm not kissing 210f all day in Florida heat. Even with A/C ON my truck kisses 210f all freaking day ! That's too hot for the Alllsion 3000 which intermittenlty stops downshift when engune at 210f.

 

Well i don't know exact fan control on M2 if this is solenoid controlled or not, if it is find solenoid and you can wire a switch inline to force the fan to stay on when you want it on, that being said the more that fan runs the worse fuel economy you are going to get. hope this helps.