Anyone install the Mercedes Benz electrically controlled fan clutch on a 403 yet? (Mike Perez)

[johnny]

That's precisely what happens. Remember, there's a difference in purpose and thus design for the two valves in the two services. In that the clutch
is designed as a viscous clutch - easy engagement. You aren't going to get it to jerk the fan, and I expect the valve is slow enough moving that the
end result will be a speed slower than wide open which speed will be relative to the pulse width.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased

 

[billvv]

A recent post on an arduino form asked...

Quote:
> I need some guidance and hopefully some leads to a like minded project.
>
> PROBLEM:Controlling an (EVC) Electronic Viscous Fan clutch with a PWM arrangement that will soft start and ramp up the engagement of the clutch. A
> viscous clutch never completely disengages nor does it totally lock up, as a point of interest.
>
> Inputs:
> (A)Coolant Temperature using a one leg sensor,
> (B)engine RPM,
> (C)Fan RPM (from 5v Fan Hall effect),
>
> Hardware: (1) 12V solenoid 2 amps max (2) GM coolant sensor (two leg) (3) GM Vehicle 5v speed sensor (4) GM 5v tachometer output

Given that a modern ECU uses, in addition to the above, Transmission Temp, AC Reference Temperature, Ambient Temperature, Inlet Air Temperature, and
Vehicle Speed to determine the pulse width for EV fans ..... it's not likely that we'll see the performance that a factory ECU provides with a
standalone PWM controller.

I've never played with the Raspberry Pi type devices, but for Arduino, I found this link has gives a
https://www.teachmemicro.com/arduino-pid-control-tutorial/

You can then play with the time constants to make the changes in fan speed slower or faster.

I wonder if it's necessary to respond to engine speed, or if just waiting until the water temperature starts to change and slowly increase/decrease
fan speed to bring it back to the setpoint is good enough.
--
Bill Van Vlack
'76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid
November 2015.