fan clutch

[Berrigan]

On my 16 there is a wire going to the base of the fan where the fan clutch is. Is this electrically energized or is it still temperature activated?

 

[kthaxton]

Electronic. When it engages.....you'll hear it.

 

[Berrigan]

Does it ever partially engage or just on and off. Also I assume it turns on when the ac is on to move air past the condenser.

 

[Joseph Donnelly]

Electrical since 2003, controlled by the ECM using temp input signal to make the decision.

 

[Ozymandias]

Todays standard on heavy truck engines.
The primitive clutches are gone since many years.

 

[Berrigan]

Todays standard on heavy truck engines.
The primitive clutches are gone since many years.

Well as you can see on my sig I went from a 98 to a 16. A lot has changed. BTW the 98 is still running the original viscous clutch.

 

[Bob4x4]

The cooling fan is pwm

 

[Powder Extreme]

The speed of the fan will vary, it's not just on and off.

 

[Ozymandias]

And it provides feedback to the ECM of actual speed versus comanded speed, so its pretty sophisticated.
For my case, i never have heard mine run full speed, i dont pull trailers.

But once when fording a deep river i had it going to limp mode when the fanblade hit the water, actual and comanded speed made the fault.

 

[Joseph Donnelly]

Fan speed is one of the ten parameters that I monitor with the Edge Insight. Its speed varies quite a bit and at higher speeds it is easily heard.

 

[Cummins12V98]

I monitor mine with my EAR! It sounds like a jet engine ramping up. Only takes a few seconds to drop coolant temp.

 

[kthaxton]

I used to be of the belief that a fan didn't do much after about 40-ish mph (maybe still the case on gassers?), but I have since witnessed otherwise with the Cummins. That sucker winds up....temps start coming down fast.

 

[Berrigan]

The cooling fan is pwm

I thought pwm was to control a motor speed. This fan is belt driven. So are you saying using a pulse width modulated power signal from the computer it controls the degree of lockup of the fan clutch? If so (imagine an ac compressor clutch) when not fully locked wouldn't the slipping cause great heat buildup and clutch failure? Bob4x4 can you explain the sequence of operation because I think I'm off base here.

 

[Powder Extreme]

I thought pwm was to control a motor speed. This fan is belt driven. So are you saying using a pulse width modulated power signal from the computer it controls the degree of lockup of the fan clutch? If so (imagine an ac compressor clutch) when not fully locked wouldn't the slipping cause great heat buildup and clutch failure? Bob4x4 can you explain the sequence of operation because I think I'm off base here.

I wonder if it's magnetic? Varying degrees of magnetic strength controlling the lockup wouldn't create any friction and extra heat. Not certain HOW it works, but having towed at a gross combined weight of over 30,000lbs numerous times, I am certain it does vary the RPM of the fan. When things get really hot and the motor is spinning 2,500rpm climbing a hill it does sound like a jet engine ramping up. You can hear the fan kick in, then hear it increase RPM and decrease RPM as necessary, meanwhile the RPM of the motor hasn't changed hardly at all.

 

[Ozymandias]

It is still viscosius, but valve is controlled by the ECM instead of the old stile air temp valve.

 

[Randy_F]

I was getting a rattling from the front of the engine, when cold. Sounded like a lose pulley. Turns out the fan clutch is bad.... Getting replaced under warranty. 2016 2600 6.7 Cummins with 13,xxx miles.