Originally Posted by sam1947

Guess you need to explan to the masses here why most new vehicles are being produced with electric fans...

Originally Posted by sam1947

...the engine mounted fan on the 150s have an electrically controlled clutch

Originally Posted by MGDfan

the Factory PCM e-fan control is still pretty 'dumb' - it still is just a basic On/Off controller based upon engine temps.

Originally Posted by MGDfan

Even the 2010 F150 is an on/off affair, even if it may have Canbus involvement

Originally Posted by jethat

Make the claim back it up with data that's the way these arguments generally go.

Originally Posted by Steve83

For the reason I stated in my FIRST post in this thread. Not even close. It involves a LOT more parameters.

Wrong again, on both counts. Fan speed varies from 5-100% based on a discrete PWM circuit (not CANbus) from the PCM, similar to the FPDM. Except the driver is integrated into the fan motor, unlike the separate driver for the pump. That's why the newest e-fans are so much better than the previous ones with relays & resistors. The aftermarket will never be able to offer a retrofit fan with that technology functioning with that level of effectiveness & efficiency.

Originally Posted by jethat

I'm not the one(s) claiming the alternator draws away a large quantity of HP in a Electric fan conversion. Make the claim back it up with data that's the way these arguments generally go. I have Googled already.

Originally Posted by MGDfan

Okay Steve - I'm intruiged - please elaborate on the "more parameters" - besides the obvious ones involving A/C cooling needs. What else does there need to be to maintain cooling effectiveness and promote efficiency?

As for the newest fans - the evidence suggests otherwise - as the 2010 F150 fans are being driven by members right now using an aftermarket variable speed controller (FKxxp) with no ill effects. So I can't see how there is an integrated driver. And these things are less than $200 for the whole assembly. Given the FPDM costs it's seems very low for a component that would contain two drivers ....

Any 2010 owners want to check to see if their fan speeds are variable?

Originally Posted by Ford 2007 PCED

Cooling Fan Clutch (trucks)
The cooling fan clutch is an electrically actuated viscous clutch that consists of 3 main elements:
a working chamber
a reservoir chamber
a cooling fan clutch actuator valve and a fan speed sensor (FSS)

The cooling fan clutch actuator valve controls the fluid flow from the reservoir into the working chamber. Once viscous fluid is in the working chamber, shearing of the fluid results in fan rotation. The cooling fan clutch actuator valve is activated with a pulse width modulated (PWM) output signal from the PCM. By opening and closing the fluid port valve, the PCM can control the cooling fan clutch speed. The cooling fan clutch speed is measured by a Hall-effect sensor and is monitored by the PCM during closed loop operation.

The PCM optimizes fan speed based on engine coolant temperature (ECT), engine oil temperature (EOT), transmission fluid temperature (TFT), intake air temperature (IAT), or air conditioning requirements. When an increased demand for fan speed is requested for vehicle cooling, the PCM monitors the fan speed through the Hall-effect sensor. If a fan speed increase is required, the PCM outputs the PWM signal to the fluid port, providing the required fan speed increase.

Originally Posted by Ford 2007 PCED

Fan Control
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure) to determine engine cooling fan needs.

For variable speed electric fan(s):

The PCM controls the fan speed and operation using a duty cycle output on the fan control variable (FCV) circuit. The fan controller (located at or integral to the engine cooling fan assembly) receives the FCV command and operates the cooling fan at the speed requested (by varying the power applied to the fan motor).

FIVE HUNDRED/FREESTYLE/MONTEGO, FUSION/MILAN/ZEPHYR, CROWN VICTORIA/GRAND MARQUIS, TOWN CAR: FCV DUTY CYCLE OUTPUT FROM PCM (negative duty cycle)
FCV Duty Cycle Command = Cooling Fan Response/Speed
Greater than 0 but less than 5% = Fan off, controller inactive
Greater than 5% but less than 10% = Fan off, controller is in active/ready state
Crown Victoria/Grand Marquis, Town Car: 10% - 90% = Linear speed increase from 20% to 100%
Five Hundred/Freestyle/Montego, Fusion/Milan/Zephyr: 30% - 90% = Linear speed increase from 50% to 100%
Greater than 90% but less than 95% = 100%
Greater than 95% but less than 100% = Fan off

For relay controlled fans:
The PCM controls the fan operation through the fan control (FC) (single speed fan applications), low fan control (LFC), medium fan control (MFC), and/or high fan control (HFC) outputs. Some applications will have the xFC circuit wired to 2 separate relays.

For 3-speed fans, although the PCM output circuits are called low, medium, and high fan control (FC), cooling fan speed is controlled by a combination of these outputs.