S60 12.7 Detroit, fan clutch won't engage.

S60 12.7 detriot.. Fan clutch won't engage and engine almost over heated. I pulled the lines from the solunoid and put a coupler in and nothing. So..it needs a hub right. I got it up to the ta and while driving in the lot it kicks in. Shut it off. Put the coupler in and still no love? Why would it work then not work? Any reason or a fluke?

 

I by passed the switch and put straight air into it by joining the 2 air lines, supply to the solunoid and the line out to the fan clutch and nothing. It won't click in. But sometimes while your driving it will? I'm stuck in a road closure now, not good.

 

They say it came with a Keyser but there is a Horton that can replace it? I'm told they both lock with positive air pressure? Mine free wheels in both positions. I was going to do it when I got to Toronto but the clutch is $484 at home in NS and $687 in Toronto. I guess that's the "bend you over your not from here we got you" price. Same thing i got in Tennessee, $600+ for the clutch and rsped on labor. I'll drive at night and get it home. I can do it myself there.

 

Made it home. Ran at night. Picked up the Kyser today. It's locked without air so air unlocks it. I also picked up a solenoid. Looks like the solunoid has power all the time to keep the fan freewheeling and removes power to lock it. So.. can I run a switch in the dash that interrupts the ground to switch it on when I want to?