Yes, all last week it was in the teens and twenties up here. I don't know if my truck is functioning properly for sure. Its running good, no codes at this time. Last week I had P0470 or EBP sensor, so I'm replacing it tomorrow.

 

Cool that makes me feel alittle better then, every since i put all this money into this truck, It seems like I drive down the road with my head out the window like a dog, just listeing for different souds, ha ha. My truck usually sets in the garage waiting to be hitched to our camper. Last week the wife starter went out, 2 days later my brake line busted on my dailey driver car, so all I had to lean on was "ole faithful" which at times has been "un faithful" as we all can understand, ha ha. I've go her car fixed, mines still broke so hopefully this truck will serve me well till I can get some time to fix the car. I hate working on cars in the cold.

 

Same here, working outside is for snowmobilers. Wait, I am one. Seriously though, I feel the same way about worrying about my truck. I've only owned this one since October, but am always researching and looking and listening since I got it.

 

Ya I bought this one 14 months ago, without researching Truck looked perfect. 3 months later I had to write a check for almost $6000.00 That was a very expensive impulse buy!! Wish I knew about this forum before I made the purchase. After I wrote the check and picked up the truck my wonderful wife informs me she is pregnant But all is well now. Just sucks buying a $ 20000.00 truck for 26000.00 and didnt even get to go camping. Oh well thats how it goes somtimes, atleast we are healthy

 

When first started it is normal for the fan to run at or above engine RPM for a bit. The fluid tends to settle when the engine is not running and it takes a few minutes for it to redistribute and warm up to archive normal operation.

When my old fan (non snow plow) was running in cool weather my fan would run around the 220-250 RPM range. When topping out a long hill it may inch up to around 4 or 5 hundred RPM then drop back.

When pulling the 5er the fan speed would constantly run 600 to 1000 rpm. Only when pulling the hills would it fully engage and catch up engine RPM. This was due to the engine, transmission and oil temperature heating up.

When fully engaged it would stay on as long as I was pulling a hill but after topping out it would stay on another minute or so and then drop back.

Really can't say what is happening with yours as we don't know what strategy your computer has and what the other variables my be causing the fan to intermittent come on.

If you can afford it, do yourself a favor and purchase the AUTOENGINUITY software and connector so you can monitor and test some of the functions.

I would say if your coolant temp, oil temp and trans temp are ok, not to worry about it.

 

Thanks for the advice, My truck is running the latest strategy, not the buzz flash. This was on a 10 minute drive home from work, and yes all temps were fine. I plug my truck in at work also, if that helps.

 

Yes! Healthy is more important than anything else.
I have been extremely fortunate with my purchase. I have changed all the fluids and installed a coolant filter and flushed it too. (Coolant was green, but clean. ) Yesterday I ordered a 4" exhaust and SCT flash programmer. Studs will be next and so on.

 

You will love the tuner, it's great with a big deal of power over stock. I'm still waiting for the exaust, for obvious reasons, but it wil come in time. Glad to see everything going well with your truck. Just updating everything, and studs made a world of difference in my confidence of the truck, so that I guess is worth somthing. Let me know how the exaust works out for ya, man I'm chomping at the bit for exaust..

 

From what I have read these fans are not like the fans of old with a viscous drive. They are now commanded by the pcm and are a HALL EFFECT pulse driven unit thus the wires going to the clutch.

 

Yes and no.....

They are Electro-viscous fan clutches.


Electro-Viscous Fan Clutch
•PCM Controlled fan speed
•Sensors monitored to control speed:
–ECT, A/C request, VSS, IAT, Trans Fluid Temp, AAT
•Solenoid controls fluid flow, regulating fan speed
•Internal hall effect sensor monitors fan speed

Here is a description of the electro viscous fan clutch. It differs from a standard fan clutch simply by the control.

The standard clutch uses a thermostat on the front side to rotate a small shaft which increases the fan speed depending on the heat coming from the radiator.

The ECM controls the electro-viscous fan clutch engagement. The control module regulates a 12-volt pulse width modulated signal (PWM) to the cooling fan relay.

The PWM signal determines the ON time of the relay. As the commanded state of the fan clutch increases, so does the ON time of the relay. This ON time directly effects the amount of time the solenoid, which is internal to the fan clutch, is energized.

When the solenoid in the fan clutch is energized, it opens the spring loaded valve and allows fluid to flow from the storage chamber to the fluid coupling of the cooling fan clutch, increasing the fan speed. When the solenoid is de-energized, the spring loaded valve closes, and blocks the path of the fluid to the fluid coupling of the fan clutch, reducing fan speed.

The fan has the ability to create a feedback signal, so the control module has an actual fan speed input. This is done with a hall effect sensor internal to the fan clutch. The control module supplies a 5-volt reference and a low reference to the hall effect sensor. The hall effect sensor returns a signal pulse through the cooling fan speed signal circuit in response to the reluctor track passing by the magnetic field of the hall effect sensor.

Diagnosis of both fan clutches is similar for the mechanical aspect. If there is any lateral movement in the drive, then the clutch is in need of replacement.

The standard fan clutch will typically spin abnormally free when it fails, and should spin with some resistance normally.

The electro-viscous clutch being electrically controlled had DTC's that will set if the speed is not what is commanded or there are open circuits to the sensors.

Leaks on either unit indicate failure of the clutch.

 

I cut my old fan up to see how it works.

 

Shooter and Lilpooh, Thanks for the explanation and pics. Very good info. Mike