Help! - fan clutch on manual switch info
 

Alright, so I need to put my stock clutch on a manual switch so that I can turn the fan on when I need it for pulling and towing.

The wiring diagram is attached. It's the second one from the top. 2003-2004 CTD. I tried running 12v's to all the wires except the ground with no luck. I have even tried completing the ground to a ground - no luck.


Anyone know the method to wire up the stock belt driven fan onto a switch?

Thanks!

Having fan clutch troubles??

not exactly. i'm trying to have the fan kick on when I want it to, now when the ecm feels its time.

i was thinking of installing new flex-lite fans, but the stocker flows more anyways, i just want the ability to turn it on when i need it. i've noticed on some grades or when getting hot that i don't hear it turning on any more. the clutch could be fried.

i want to see if anyone else on here knows how to wire it or who tried this. i didn't find any possible combination from the available wires to do this.

IDK if I would add a switch. Might backfeed the ground or power through a sensor or the ECM and fry all kinds of stuff or keep setting codes.

good call. but i cut all the wires to avoid this. there has to be a way to wire it directly and not even use the ECM. I can rewire everything if I can't figure it out. I'd hate to drop 500 on new fans that are less effecient for no reason. All I want is the ability to turn on/off when I want. :)

thanks bud.

That's going to be the tough part, trying to wire it so it doesn't throw codes.

5.9L DIESEL (ELECTRONICALLY CONTROLLED FAN DRIVE)
The Engine Control Module (ECM) controls the level
of engagement of the electronically controlled viscous
fan clutch by monitoring coolant temperature, intake
manifold temperature, air conditioning pressure and
transmission oil temperature. Based on cooling
requirements, the ECM sends a signal to the viscous
fan clutch to increase or decrease the fan speed.
Fan speed is monitored by the ECM. Fan speeds
above or below a calibrated threshold will set a DTC.
Circuit concerns will also set fan clutch DTC’s.

good info!

but when I cut the wires or disconnected the connector... it didn't throw any codes at all.

One other thing about a switch, it's all or nothing. So this is going to kill the fuel mileage.

agreed. but i'm not looking for fuel mileage increases. i have really large injectors and big turbos and big tires. i'm only seeing 13mpg on 740hp settings. its a competition type rig and i'd rather have it all or nothing, if you know what i mean. :w2::rocking:

it looks like you maybe need 5 volts to kick the clutch, not 12 maybe