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Electric cooling fan clutch.

G

great white

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So, now I've got your attention.

:hihi:

We all know (or should know) about the Horton electric fan clutches and their inherent benefits.

I think is was Missy that had one on her truck.

But, they're hell and gone expensive!

Now, there's lots of stock engine driven electric fan clutches out there and they're much more affordable than a Horton unit. Cleaner install also. The ones I've seen thread on like a stocker.

Ford, gm and Dodge use them on many vehicles.

As mentioned, most of them are the "spin on" type like the 2000 and up water pumps.

Has anyone ever seen if one would spin on to the later GM water pump?

If my pump wasn't brand new (1 year old and the four bolt), I'd give it a try at the local parts store. I may yet, I know a couple guys that work there.

Then and appropriate fan would have to be found to bolt up. A stock one designed for the selected clutch (ford/gm/dodge) would probably do it.

Then, a temp switch or a manual switch could turn it on or off.

I'm going at this with a bit of a hidden reason; since I can program my own PCM's, I can designate an output that would turn the clutch on and off at a programmed temp (well, not on an L56 truck, no spare pins to use).

Something like on at 200 and off at 190.

That sounds like a bit of "cats ass" for our trucks.

Stock parts (for easily sourced replacements), programmable on/off, manual override on/off, true freewheeling when desired and without the cost of a Horton.

So; anyone work at a parts store and want check it out?

I'm up for programming a couple PCM's if someone wants to try that also.....although I've got limitations on which years I can program right now.
 
Yeah . . . You already *know* you have my attention. :grin: The electric clutch is only part of one of the upgrades I want to do and am still in the research stage. PM me if you want to go over details and keep the thread clean.
 
I sent the "CPA" a pm, this is something I would like to be involved in so I am going to try and help with the R&R as much as I can, my only trouble is a fully manual truck, may be some searching for some high tech things.
 
Gentle reminder a fan clutch off a 2003 is nearly 10 years old. Electric controlled or spring thermal they still loose 200 RPM per year and are worthless after 5 years. Worthless means peak holding power is gone as the fan is spinning 1,000 RPM slower at 5 years old at full lockup. New the EV fan clutches are well north of $500.00. You want a recent take off sold used. Like they put e-fans on a new truck for whatever reason.

You can reline the clutch surfaces on a Horton Fan clutch.

The cut wires mean the person removing it didn't know and cut them or more likely as the wires run in front of the fan: they got sucked through the fan.

Diesel fan clutches are the way to go. A Trailblazer has used the EV clutch till the last two years of production. The General's cost cutting bit them in the A... The early clutches were not strong enough, later ones had the valves disintegrate. The Trailblazer PCM is a good place to look for programming. However, the temp values GM used are garbage. Things run way too hot and AC performance suffers. So use your own numbers. The Trailblazer also suffered from a bad stack seal over the top of the radiator that blasts the condenser with hot under hood air at the top and a radiator that is too thin. The Trailblazer fan clutch although mounted to a 21" fan is not strong enough as the fan has less pitch and will see engine speeds of 5000-6500 RPM plus the overdrive ratio of the water pump pulley. The diesel fan sees lower RPM with a thicker radiator stack so it needs a higher pitch fan with more fan clutch torque transfer.

The valve in the EV, electro-viscous fan clutch, is intended to be controlled by PWM with an RPM sensor to provide feedback and compensate for age related slowdown. It will also set a code if the fan clutch is not running at the set RPM - too slow or too fast. The wires run in a rubber hose in front of the fan.

There is absolutely no reason they could not be used as an on off type of clutch. However, the clutch will still have morning sickness and be locked up for 1-2 min on a cold start. The Horton does not suffer from this.

You could also run the fan in PWM steps ignoring the feedback RPM. This would be a great way to avoid the on-off only of the Horton. It would also be able to get the fan on quicker with a WOT mountain climb. Aka less temp swings.

Horton's can be found on hummer 6.5's and have both v-belt and serpentine pulleys available. You can swap pulleys as they are not directional. Aka available used and can be rebuilt with your pulley choice.
 
I have looked at different set ups on big trucks, ( I drive one ) and they, or most turn on & off with air, and they are kinda big, I have a air system for my air bags now, but the clutches on the big rigs are BIG, don't think they will work either.????
 
Somewhere I posted the site and parts available for the clutches. Used you can get them for $50.00 v belt style and swap the pulley for an additional part cost. No one wants then from their used hummer engines going into pickups...

You add hydraulic hose to the power steering pump that is no worse than replacing the oil cooler lines with something better. Return line gets the valve with a 't' to the fan clutch. Pressure holds the fan off as I recall. I think it puts some pressure in the return line to pop the clutch while bypassing at a specific pressure to still allow flow.

You add one hydraulic valve. I am not sure if it is 12 or 24 volt. This could be an issue.

You add a ECT temperature switch (or control of some sort). An AC pressure switch to kick on the fan for condenser pressure/temp is a good idea. Not sure Military stuff even has AC?

The hose going to the front of the clutch and a secure hold down in front of the fan to the frame for the hose would take a little fab work.

The fan clutch bearing and seals may need oil, otherwise compressed air could work. But KISS as you already have a PS pump available and this is what the military design used.

Missy's fan clutch was electric! See eBay for pics.
http://www.thetruckstop.us/forum/sh...-pump-for-6-5-with-Horton-electric-fan-clutch

Thread on the hydraulic unit with the site and links. Gov't sales only so no real vendor issues... They are NOT the low bidder!!!
http://www.thetruckstop.us/forum/sh...erpentine-belt-drive-fan-clutch-Fort-Lewis-WA

Here is the specific post with parts breakdown and the cost to go Hummer fan clutch...
http://www.thetruckstop.us/forum/sh...-Fort-Lewis-WA&p=308459&viewfull=1#post308459
 
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