id like to see what you come up with as well. I have an lml so I have the electric clutch already but be interesting to see what you come up with.

 

Well i have bin playing with it some, had a few HG jobs that got in the way and now an LBZ with some serious bottem end issues, and this is stuff i do on the side, works not bin very busy on the LML's, which is a good thing. but if you do ground the relay it does command the fan on full. i gotta get a junkyard one with harness to put on my LBZ to put into the real world

 

Any headway on this project?!
I'm looking to swap to a LML fan clutch also. I actually purchased a new LML unit a few months ago, but thats as far as I have got with the swap.

 

i wont lie dude, i havnt had time at all, if you bought the fan clutch did you get the jumper harness and the pigtail from GM? if not go to a junk yard and cut them off, i am 99% sure it will work. its a 5 wire pigtail but 3 wires are for the ECM to see the speed the fan is going, which we just want it on or Off, if you wire black wire to ground(this is at the 5 pin connector for the fan clutch, and the WHITE wire will be the wire you apply 12v to, make sure you install a 10 amp fuse, and use a relay to control it, its probably less then 5 amps to make it run, if you have any issues Email me mebob2001@gmail.com and we will start texting and make it work.
i am hoping i can get this engine build done and the other mounting jobs done. i gotta open my own shop... working at a dealer and doing work on the side is getting to be a little much
Anyways Keep me posted if you get going before me dude

 

I have a lot going myself and just haven't had time figure out how I want to do it. Now that it's warm again I need to make time and get it done.
The new clutch came with a pig tail about 6" long and my plan was to tap into the wires I need right there.
My original plan was to wire it up exactly as you describe. But in my internet travels it seems like there is some dispute if it actually is that simple to make work. The factory setup uses PWM to modulate fan speed. So the unknown is will it produce a full-lock situation if you feed it a straight 12v when it is expecting a PWM signal? One thread mentions the fan defaults to locked, so it would need 12v to unlock, not sure if that is really the case.
Could you send me your wiring diagram above? For some reason it's way too small to read on my computer.

 

i understand why they seems to think it being PWM and direct 12V being an issue. but its a fucking electro-magnet they only use PWM to keep drag off the engine for that little extra boost in fuel milage. plug when im watching the scan tool during a service regen it is commanded on at 100%. now if they want me to go all nerd on it i can grab my amp clamp and my verdict D7 and current ramp the white wire and or current ramp it at 50% PWM, so your going to see X number of amp and 12V being applied directly on and off. i am not an electrical expert but i know enough to say who gives a fuck? it makes sence it should work so try it!. this is one time i wish i had an LB7 LLY that fan clutch is a joke to replace, being an LBZ slight more of a pain. but NOW i think i am going to just try it on my buddies LML and jump the relay

 

It makes sense to me it should work also, but I'm not sure I want to be the guinea pig to try it and hopefully not burn up a new clutch. I noticed that some of the electric fan controllers use a Pwm signal to modulate fan speed. That might be a good option since ideally the clutch would lock up on its own at a pre determined temperature and you could have a override switch to manually lock lower.

 

Well to burn one up i highly dought i've watched them scream out back at 100% duty cycle on 2011's doing reductant quality test's for 70 min at a time and just time out, go for a 20 mile drive and do the test again. as for burning it up i really can't see that happening. and making a controller seems pointless to me. its eathor you want locked or not.

Anyways ill try and get the ball rolling shortly. i am shocked NO ONES done this yet.

 

Even the electric controlled viscous fan clutches will do it. When the fan clutch is cold, the fluid in the clutch is very thick, and engages. Once that 10,000 weight(or thicker for some clutches) silicone oil warms up, it returns to normal operation. The old style fan clutch uses a thermal spring to control the engagement, an electro viscous clutch replaces the bi thermal spring with an rpm sensor and an electric solenoid to take the place of the bi thermal spring that origanally engaged the clutch. So even though its an electric control, it still has all the same quirks of it's mechanical predecessor.

　

...

 

Well i have bin putting though into it, and if we remove the clutch fan then coolant temp will probbally fluctuate a lot more, so if your not watching the temp all the time it might be a bad idea unless your towing all the time and watch that temp. i've talked to guys with an LBZ/LMM with worn out fan clutch and they said they had to play with the temps alot more, so a controller would be a good idea, i for sure can not sort that out.

and for supplying 12 directly to it, im going to use my vedict and back prob the white wire to see what is going on at 100% duty cycle. just boils down to when i get to it

 

I would be very interested to know what type of signal you see at 100% duty cycle.

I don't think it would be a huge issue having it just on a switch. I'm not sure if I have ever had the fan clutch lock when I'm not towing, and I live in an area with steep hills and 100+ degree summer days.

If the PWM signal is in fact unnecessary my plan was to use something simple like this JEGS Performance Products 10561, JEGS Electric Fan Wiring Harness Kits | JEGS Performance Products and then of coarse wire a toggle switch to close the relay at lower temps when desired.

 

Pulled on grade in eastern Utah on I 70 W yesterday night with a 30 ft camper. Coolant with up to 221 then fan came in. Grade reduced but still uphill. Fan off at 190. Grade increased in steepness. Coolant was up to 226 before fan kicked back in.

 

as chevor pointed out there are fan clutches out there that can control the heat situation very easily, but on a side note i mentioned it to our electrical guy today, and he mentioned using a rheostat to control the voltage, how its an electromagnet a rheostat might work out quite well, so now to get everything to gethor and get off my lazy ass and attempt it purely for curiosity. guy's

 

Would be interested also if the LBZ fan clutch can be swapped to the electric fan clutch. My factory fan clutch wasn't working properly (so I thought), when first started and it's 95 plus degrees outside and with remote start to cool down with the a/c and it would not work properly since no air movement was happening. Purchased a new clutch and same problem. Plus does anyone know what the cfm is for the LBZ fan anyway? Been thinking about electric fan but have seen both good and bad reviews for it. Any help would be appreciated.

 

I would start with cleaning your cooling stack. If the fan slightly spinning at idle can't keep the condenser cool, I'm gonna guess you have very restrictive air flow.


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Clean your stack as kow said. You will notice a differnce. Or a 2886 fan clutch or whatever Malibu and kow are using

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Not so, everything is new, was in an accident and the entire front end was replaced. That's when I replaced everything on the front of the engine since it was easy access. Sometimes it works correctly (especially when it's cold outside) and you can hear it pulling the air and then sometimes (when it's really hot) it's quiet. Sometimes when just driving down the freeway the fan will kick in and roars like a lion and you can feel the power draw it has, like loosing 20 plus horses. The sad part of it all to me beside the aggravation, is spending the money for a new one and it does the same exact thing as the old one. XDP has this listed as a replacement for the clutch fan.
Flex-a-lite 284 Direct-Fit Dual Electric Cooling Fans

 

Should the fan not running on a cold start really affect the a/c?


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The LMM Kodiaks used an electric/viscous clutch similar to the LML light duty trucks, GM left the LBZ/LMM ECM pin outs empty on the light duty trucks. Just don't have equipment to test if their operational on the light duty truck tune. Go to the links for the Medium Duty truck I posted earlier for more information and compare them to the LBZ/LMM light duty truck...

ECM C-1 connector

4 D-Blu 2364 Cooling fan speed

28 WH/BL 2366 Cooling fan clutch control

45 L-GRN 2032 coolant temperature signal

 

Not trying to highjack this thread but I made an observation.

With my 2012 duramax, I remember hearing all fan noise when starting the truck and driving around.

Now that I have the 2015, I cannot think of a time when hearing the fan.

What has changed?

 

So I had some time today and decided to swap clutches and feed the lml unit a straight 12v and see what happens. I figured the worst case is I burn up a new fan clutch .
So after a very short time I hit a road block. The LMM fan is completely different and will not bolt to the LML clutch. I could have sworn I had read they were the same when I decided to jump into this.
So anyone know the dimensions of the LML fan? Or maybe a different fan exist that will bolt to the lml clutch and fit inside the LMM shroud......

 

You can't just drill new holes in the fan?


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It doesn't appear so. To be honest I didn't tear it completely down to compare side by side. When I realized it wasn't going to work I reassembled everything.
The LMM fan has a small 4-bolt pattern on the back of the clutch. (engine side) The LML clutch has a 4-bolt pattern that is substantially wider and has studs that point towards the radiator. The fan must be shaped completely different.

 

Has anyone figured this out? I was thinking of setting up a LML Electric fan clutch with a simple switch like this. https://store.switchpros.com/sp-910...-9100-bezel-style-8-switch-panel-power-system-with-concealed-mounting-hardware/

 

I am not sure i would call that a simple switch, however based off skimming the first few posts (i cant make out the words on the diagram on page 1) is sounds like you just need to trigger the relay to energize the fan. a simple 30 cent SPST switch would work just as well as that fancy switch, unless you plan to add a bunch of extra stuff that utilizes all those extra buttons. (even if you are, this is like a 35$ arduino project not a 500$ investment, that thing is INSANELY over priced, my 2 cents.)

 

Thanks, I realize that's an expensive switch, but i do plan on adding a bunch of accessories to the my duramax suburban, so it would make the interior switch layout and wiring of the accessories easier in the long run.

 

Im currently playing with this idea. I currently have one of the lml clutches installed but i believe its defective as im unable to get it to lock up. U have to get a fan from a dmax van. It has the bolt pattern of the new clutch but had the diameter of the older dmaxs. I currently have it installed on a lb7 with a custom module supplying pwm.

 

Anything become of this?

Anyone else?