Electric Fan clutch

[smokymtn65]

Where did you install the Hayden temp sensor?

 

[THEFERMANATOR]

Flex-a-lite now makes a pwm controller that I think would work very well on one of these evc's. It starts out at 40% and ramps up as you get closer to your preset temp. It also has an ac input wire on it.

 

[Twisted Steel Performance]

Logical place for the temp prob would be the p/s head as it's in the rear of the head/motor..

 

[ak diesel driver]

That's where mine is

 

[Husker6.5]

Logical place for the temp prob would be the p/s head as it's in the rear of the head/motor..

Perfect use for that pipe plugged unused port, that when used as the Driver Side head, is for the temperature gauge sender.

 

[Duvall]

In case anyone was curious as to how these work or the wiring.

Here is a wiring diagram. In the OEM design they were controlled by the ECM and a solid state relay to pulse the 12 volts on and off to control the fan speed.


Zoomed in a little



Here is a Youtube video explaining how the clutch works. This video is for the type that is controlled by the thermo coil on the front. In the electric type the valve for the viscous fluid is opened by the 12 volt signal.

 

[THEFERMANATOR]

In case anyone was curious as to how these work or the wiring.

Here is a wiring diagram. In the OEM design they were controlled by the ECM and a solid state relay to pulse the 12 volts on and off to control the fan speed.

View attachment 59728
Zoomed in a little

View attachment 59730

Here is a Youtube video explaining how the clutch works. This video is for the type that is controlled by the thermo coil on the front. In the electric type the valve for the viscous fluid is opened by the 12 volt signal.

The EVC clutch still uses a thermal coil. Instead of the airflow across the radiator heating the coil, the ECM controls it by applying power to heat the coil. More voltage = a hotter coil which gives more clutch engagement, and less current equals less engagement. This is why there can be up to a minute delay between the ECM calling for the fan, and it actually engaging(this is rare as it normally takes less than 30 seconds, but there is a delay).

 

[Duvall]

The EVC clutch still uses a thermal coil. Instead of the airflow across the radiator heating the coil, the ECM controls it by applying power to heat the coil. More voltage = a hotter coil which gives more clutch engagement, and less current equals less engagement. This is why there can be up to a minute delay between the ECM calling for the fan, and it actually engaging(this is rare as it normally takes less than 30 seconds, but there is a delay).

Thank you for clarifying that.
I see the electrical drawing indicated it as a heater, but I was unsure after researching the wrong information. I was watching a different youtube video and he was talking about a solenoid inside the clutch assembly. I thought it was a little too small in there for a hydraulic type solenoid.

 

[Duvall]

Dorman 645-500 is the electrical connector that fits the fan clutch.

It is available from RockAuto and Amazon.

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[Will L.]

So lets dig this one up.
@ak diesel driver and @smokymtn65 updates, responses, alterations made, etc.?

I Know a few others have jumped on this setup recently but haven’t had enough run time to speak up and in one case he never speaks up, he and I just text (and I thought my tin foil hat was tight) haha.
My progress on the spinon to hmmwv clutch adapter has been zero positive gain. Only ways to not do it so far, and 2 new theories to try building next. My testing is being done on a bench with electric motor and load cell. Much safer and cheaper than breaking in a real rig. So as of currently- this electroviscous adaptation of ak diesel driver’s is still a strong first place it seems. It will surely be lower than my adapter set up would ever be.

As to the depth of fan issue brought up by Warwagon for peak performance...How far forward should the fan be for your truck?

 

[Will L.]

Oh yeah, and if anyone running this can do the rpm test with the reflective tape style tachometer, (usually $30ish) to read pulley speed vs fan speed when engaged- that would be awesome.

 

[ak diesel driver]

WOW didn't realize I had done this 3 years ago. Anyways I checked the fan speed vs pulley speed this evening. As far I can tell they are the same speed. At idle pulley was reading 870ish fan 480ish. With it engaged the fan was the same as pulley. Had my boy try to hold a steady 2k rpm and checked it then, pulley was 2370ish and fan was 2370 ish. Wish there was a better way to hold engine speed steady. Plus if your hand wiggles a little bit readings bounce around some too. There you go Will even after 3 years it's still the same pulley speed.

 

[Will L.]

WWWWOOOOWWWW!!!

the whole thing of % of lockup being less than 100% has been from the manufacturers of fan clutches
And before that from the mechanics courses from public high school to U.T.I. in Az, and other college level courses, and training at places like GM and Ford. Then other folks like Kennedy- but to be fair maybe he is doing what most of us did- repeat what the manufacturers are saying about them.

I gave my reflective tach away but am ordering another tonight to check even the Toyotas, My Sons dodge which we just replaced this weekend, and anything else I can get my hands on.
This is HUGE imo. If anyone else has a tach they can check it with and maybe post Youtube, that would be awesome.

Maybe it’s only this type of unit that does it? Maybe it’s the heavy duty ones?

I know I was always taught replace them every 5 years because they loose 5% per year. So did this one have 115% speed when new? Haha- but really... I get that over time there is loss. Usually my favorite experience has been when the silicone leaks out and dirt builds up on it it gets weak. Try cleaning the bi metal coil but heat it up with heat gun and heat up the new one and you can tell a difference.

Am I missing something here? Did I (and many many others) just get hood wink d in the name of more sales? I am quite sure my son’s viscous fanclutch we just changed (01 dodge 1500 5.9 gasser w/“ max cooling”) was the original unit- as in 20 years old. It did make a difference. If it started at 100% it should be at 35%. No way it was that low. Think I will read the new one then reinstall the old one just to measure.

My nephew is driving his 88 k2500 6.2 more now. Maybe I measure his old one and buy him a new one and teach him how to while at it and measure that too.

I feel like a kid learning certain things about Santa Clause that jic one reads this with his Dad wont get covered.

MAN!

 

[ak diesel driver]

There's 2 things I'm going to eventually change. First I want an LED on the dash to show when it's commanded to be engaged so I can fine tune it easier. Second I am seriously considering moving the temp probe to the crossover block off plate, I've had to replace it once already. I think the exhaust heat is cooking the sender. The bakelite center was actually loose in the brass and not just a little it was quite a bit

 

[Husker6.5]

That's quite possible, or it could be cheaply made temperature senders, too. Couldn't hurt to tap the block off plate and mount the sender there. If it fails again, probably the sender and not the location, time to try a different brand/mfr? You do have the temp sender energizing a relay to power the clutch and not having the amperage from the clutch running directly through the sender when it engages? That could overheat the sender and cause the core failure of the sender from overheating that you describe.

 

[Will L.]

Please draw up or show how you wired everything please, including what you’re doing with the display light.

On the sensor location, I fully get why that spot, but personally I do a mechanical temp gauge there. Because you can adjust it to what ever engage point you want, you could read the high temp from anywhere you want and match temp from the other location and set it accordingly.

 

[JayTheCPA]

FWIW, I have a Euro thermo viscous clutch that is likely original to the vehicle. Going on a couple decades and hundreds of thousands of miles. There was one time when I chased cooling issues and looked toward the clutch, but the mechanic replaced the water pump and thermostat instead and things went back to normal.

 

[Will L.]

Ya know, It has just been taught - by everyone about the 5 year 5% rule. Like always change oil at 3,000 miles. I never questioned it. But thinking about that honey thickness goo, loosing so mush out the little seal area of the bi metal coil- It should make a monstrous mess. I know the Toyota guys rebuild them and control the volume they use to get different desired results. I wonder how much really has to be lost to affect it. It is in a constant pump scenario in there. hmm.

 

[THEFERMANATOR]

The OEM's say not to replace the evc clutch unless there is a problem. They don't lose performance like a regular thermal viscous clutch does. That said, there is ALOT of grenaded Dodge AC compressors from these evc's getting delayed engagement. They will still lock the clutch in, but over time they start taking longer and longer to lock in.

 

[FellowTraveler]

There's 2 things I'm going to eventually change. First I want an LED on the dash to show when it's commanded to be engaged so I can fine tune it easier. Second I am seriously considering moving the temp probe to the crossover block off plate, I've had to replace it once already. I think the exhaust heat is cooking the sender. The bakelite center was actually loose in the brass and not just a little it was quite a bit

Have you considered steaming being the issue when sensor is moved to that rear block-off plate?