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Electric Fan clutch

I haven't tried hooking power to the voltage reference because I'm not sure what voltage it uses. I also haven't hooked haven't tried anything on the speed signal wire
 
Les,

I am no expert but this is my thought to test it. Someone chime in if you think this is wrong.

1st confirm the fan works like this....

Pin 3 and 4 could be left unhooked as you can't read the speed.

If you supply 12v (might want to fuse it at 20 amp) to pin 2 going into fan

Ground pin 5 of fan and it should lock up to max engagement.

If you get nothing pin 5 may be a ground for another reason??? not sure why it would need an extra ground to function.

If that doesn't get engagement then I would also ground 6 of fan at the same time it should be max engagement. and Pin 6 is the actual end circuit of the solenoid.

If you still get nothing the clutch is probably bad.

Then we can talk about how your PWM control circuit works.

Just not sure what is difference in grounding 5 vs 6 for forced max lockup.
Not sure what Ford guys are doing with grounding blue 6 wire to force max engagement I suspect its a speed signal override of some type that covers up or grounds the speed signal so PCM just commands to ramp up for max in its speed control algorithm. This could be an easy way to quickly max fan for any PCM reason.

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Thefermanator did say sometimes you can burn up a PWM solenoid if incorrect frequency similar to over duty cycling something but I don't THINK this will happen because I thought I understood Hayden said you should be able to supply 12v and ground to engage fully. And I think this should be a heavy duty solenoid capable of 100% duty cycle for max engagement. Just because its so important not to overheat the engine.
 
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Thanks Shiker I believe that worked. The Hayden engineer told me to hook power to pin 6. When I grounded it I could see the hub move a little bit. Took it for a spin and I think I could hear it but it's not real loud. When I got back the clutch was much firmer than it had been. So for a final on the wiring were looking at grounding both pin 5&6 and power to pin 2. So I'm going to hook both ground wires to the fan controller. Next up I need to see if I can find a better fan. The 2 I have in mind to look at more closely are the dmax fan and one off a 6.0 powerstroke.
 
The gasser fan turning at diesel RPM's will be pretty quiet. You need to raise the RPM's up to 1200 or so, then with the hood open engage the fan clutch after the engine has run long enough for the fan clutch to get past it's morning sickness phase. If it is working, you should be able to feel the difference in airflow coming off of the fan. I know I worked on a FORD EXPLORER with that style clutch, and at idle you couldn't hear the fan at all due to how the fan was designed.
 
This is how I think it works.... steady 12v power to pin 2 and grounding pin 5 of the fan clutch is like a thermal coil mechanical spring shutting the port in a fan clutch to make it lock up like any ole hydraulic fan clutch. This will be max speed it can achieve. These will be the only wires you need to control.

Pin 3 reference voltage (5V???) is to power a sensor that measures the actual fan speed. The fan clutch sends the actual fan speed back to the PCM on pin 4. Maybe can assume 5V means fastest and 0V means slowest. It may be digitized. What ever the PCM can understand it for the speed control algorithm.
The PCM has a subroutine to adjust the fan speed as needed desired vs actual and sends a PWM signal to the [PCM Power Relay] that pulse width modulates the power to the pin 2 on the fan clutch to achieve desired speed. Pin 6 is a PCM switched ground that will cover or mask the returning signal on pin 4 such that the PCM sees a slow speed (pin4) and PCM will increase desired speed according to algorithm and quickly ramps up to 100% PWM. Or 12 volts to pin 2 on fan clutch acting like a thermal spring shutting on a classic fan clutch (same as paragraph 1). Various PCM safeties might be able to ground pin 6 its like an emergency max cooling needed override.

Now what will be tricky is what PWM frequency is needed to control a partial lockup if you want. And where we might need to know frequency limits of fan clutch solenoid. Trying to turn it on and off too fast or too much might burn it up but 12volt steady won't. Similar to how you can burn up an electric motor or other solenoid turning it on and off too frequently but it won't burn up running normally. But my guess its pretty forgiving. Maybe more important another big question is the PWM frequency has to match what the silicone fluid can mechanically react to or you may be switching the valve but the clutch or fluid can't mechanically work that fast. And or you don't want it to surge or oscillate the speed annoyingly.
 
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ak diesel driver said:
Took it for a spin and I think I could hear it but it's not real loud.
Click to expand...

My experience with fan noise on lock-up and 'morning-sickness' is that it is not that loud and it is tough to hear the DMax fan above the motor. Can definitely tell the difference, but it sounds more like the motor is a little louder as opposed to a roaring fan.
 
JayTheCPA said:
My experience with fan noise on lock-up and 'morning-sickness' is that it is not that loud and it is tough to hear the DMax fan above the motor. Can definitely tell the difference, but it sounds more like the motor is a little louder as opposed to a roaring fan.
Click to expand...
He's using the gasser fan blade from the FORD, and they are very quiet. As to the duramax fan blade, I can definately hear mine when its cold.
 
Understand that. Just wanted to give a more apples comparison. In my DI rig I can definitely hear the fan, but on the Burb with the DMax fan, it is much less noticeable as the motor is much louder ;) Point is that even when Les finds a diesel rated fan, the noise is not what one expects and sounds more like the motor getting a bit louder as opposed to a roaring fan. Or at least that is how it is for me :)
 
i need to know all the dimensions where it bolts to the clutch. not just the bolt pattern. one of the issues is finding a fan with a large enough "hole" if you will to fit over the clutch
 
OK, sorry for delay, was at RV show all day.

Duramax fan hub bore is 3.240" (82mm).
Bolt circle is 3.815" (97mm)
 
Wow NVW, that joke stalled the thread for two months!

Have you ever figure out if you can get 100% lock up from that, and if not how close?

I have a guy that's supposed to be bringing me a hmmwv clutch to look at in person. Wondering if I can it modify to work with spin on style waterpump.
 
Will L. said:
Wow NVW, that joke stalled the thread for two months!

Have you ever figure out if you can get 100% lock up from that, and if not how close?

I have a guy that's supposed to be bringing me a hmmwv clutch to look at in person. Wondering if I can it modify to work with spin on style waterpump.
Click to expand...
Well I have to apologize for the Highjack.:D
 
Don't know what % the lock up is. The fan is so quiet I can't tell when it's on. I did tow a small load the other day and even with my grill screen on I couldn't get the temp to move more than a couple of degrees.
 
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