A better CRD fan? Is this what I think it is?

Mountainman · **Posted:** Sun Feb 03, 2019 3:02 pm

https://www.ebay.com/itm/GENUINE-GM-OEM ... SwMflcDsH3

APC9199 · **Posted:** Sun Feb 03, 2019 3:16 pm

An electrically actuated fan clutch that still retains the viscous element for overheating in case the electrical fails. That would be awesome if configured properly, but as with most aftermarket electrical components, how would you make it work with the CRD? You would need access to the computer that controls it and would have to create all the cooling maps manually. GDE might be able to figure out how to do that, but someone would have to confirm that the electrical system even exists or can be added to install it.

Certainly an interesting idea!

Mountainman · **Posted:** Sun Feb 03, 2019 8:59 pm

I was thinking sasquatch might be interested in building a controller for it. All you need are the temp sender, 12v and ground wires I'd think.

Actually, I could probably wire up my current electric fan controller to operate it.
Wouldnt the electric portion be all or nothing (12v or 0v)?

It also has viscous actuation?

APC9199 · **Posted:** Mon Feb 04, 2019 12:13 pm

I suppose it could be simply wired using the temp sender for on/off signal. I don't know if it has any type of PWM to be able to control fan speed or "jerk"?

It appears to still have the heatsink that is evident of a viscous fan clutch. I assume this is there in case the electronics fail and the motor overheats, allowing for the fan to still kick on at some point to save the motor. If it were purely electronic I would see no need for the heat sink.

Mountainman · **Posted:** Mon Feb 04, 2019 12:57 pm

APC9199 wrote:

I suppose it could be simply wired using the temp sender for on/off signal. I don't know if it has any type of PWM to be able to control fan speed or "jerk"?

It appears to still have the heatsink that is evident of a viscous fan clutch. I assume this is there in case the electronics fail and the motor overheats, allowing for the fan to still kick on at some point to save the motor. If it were purely electronic I would see no need for the heat sink.

Yeah, perhaps the electromagnetic clutch is tied to the viscous apparatus, and thereby "feathers the clutch" via PWM?
Just from the look of it though, I'd think its just a tiny clutch that operates like our viscous heater?

I guess we'll have to find some specs on it. I was actually searching for the fan hub assembly as a possible less expensive replacement as the engines are VM based, but I had no luck finding it.

TKB4 · **Posted:** Mon Feb 04, 2019 1:22 pm

Definitely interesting

GordnadoCRD · **Posted:** Tue Feb 05, 2019 12:01 am

The electrical control for those uses an ECM controlled PWM circuit. I do not know what the maximum duty cycle is, but they might be usable with an adjustable voltage controller. I haven't had any chance to play with them and find out.

Mountainman · **Posted:** Tue Feb 05, 2019 12:44 am

GordnadoCRD wrote:

The electrical control for those uses an ECM controlled PWM circuit. I do not know what the maximum duty cycle is, but they might be usable with an adjustable voltage controller. I haven't had any chance to play with them and find out.

Interesting, can't beat the V variability of an IGBT I guess.
I bet if we fed it full duty cycle (V) all at once, that it wouldnt last long. Pipe dream I'm afraid.
I'm trying to imagine the clutch mechanism :dizzy:

I found a forum where they said they are having chronic failures, but GMC hadn't identified the problem yet (clutch or controller), so might not be a good option regardless.

Back to WW's excellent alternative :BINGO:

GordnadoCRD · **Posted:** Tue Feb 05, 2019 10:02 pm

not a "clutch" as one would think of it. It's a fluid coupling with a type of silicon fluid that increases viscosity with voltage, but I don't know what the limits are.

Mountainman · **Posted:** Wed Feb 06, 2019 1:36 pm

GordnadoCRD wrote:

not a "clutch" as one would think of it. It's a fluid coupling with a type of silicon fluid that increases viscosity with voltage, but I don't know what the limits are.

Hmm, that has me wondering if it has fins like a torque converter. That's one heck of a difference in viscosity either way, crazy physics!

mass-hole · **Posted:** Wed Feb 06, 2019 6:23 pm

Why couldnt we just use the oe fan wiring assuming this could handle a direct 12v? It would only be on/off, but so what. We have access to the maps in the tuning.

Mountainman · **Posted:** Wed Feb 06, 2019 7:15 pm

mass-hole wrote:

Why couldnt we just use the oe fan wiring assuming this could handle a direct 12v? It would only be on/off, but so what. We have access to the maps in the tuning.

Hmm, just the clutch isn't crazy expensive. I guess someone could buy one, apply 12v, and see if it locks up well, and doesn't let the smoke out. I asked the local junkyards, but not many totaled yet in the country, and they seem to be keeping the engines whole. The one I found was about $10k just for the complete engine.

GordnadoCRD · **Posted:** Wed Feb 06, 2019 10:31 pm

I haven't tried it so I don't know the results of straight 12v, or a resisted circuit. I'm fairly certain it would work for a while, but have no idea how long the "while" would be.

THat said, I can't imagine we are the first people to have thought of this. I bet there is someone out there that has tried it and posted the results. Google might eventually find them, but I haven''t taken the time to search.

Not exactly what we're looking for, but perhaps some ideas & info.
https://www.dieselgiant.com/mercedeselectricfaninstall.htm

Closer, bottom of page. This one works differently, more like a valve-controlled torque converter, controlling the flow of the silicon gel rather than the viscosity.
https://www.haydenauto.com/Featured%20Products-Fan%20Clutches%20and%20Fan%20Blades/Content.aspx
https://www.haydenauto.com/Featured%20Products-Digital%20Fan%20Controller/Content.aspx

A better CRD fan? Is this what I think it is?

Who is online