Sevir

After reading the article in DP magazine. i am looking at putting a electric fan in my truck. Was wondering if anyone has done this and does it really improve that much fuel milage. I can care less about the power gain, i want it for the faster warm up and the increase fuel milage. i was going to put a cutout switch on it for when i first start the truck up it wont run at all until i engage the switch at the engine temp i want it at.

Thanks

madhat

I was thinking somewhat the same thing, good post. Waiting for an answer from one of our many diesel guru's with baited breath...

kokalit

I read same article and was interested, however, From Flex-A-Lite's website...

"Electric fans are not recommended for primary diesel engine cooling when the combined gross vehicle weight (CGVW) exceeds 18,000 pounds (truck, trailer and load)"

Plus what they have listed is from 1994-2002, couldn't find anything for newer, but didn't spend a lot of time looking and didn't email or call them.

http://www.flex-a-lite.com/auto/html/262-diesel.html

vzdude

I have been contemplating the same thing. Just trying to figure out a way to get around the ECM's need to monitor the fan speed and electrically engage the clutch. I guess if quad could make a module.....uhhmm(hint, hint)......that would be cool! Would be the first to sign up for beta on that! I have a DRBIII and a lot of know how quad! How can I help?

HOV

What? Why would this be necessary? I've never heard the fan run on my truck. The cooling system is head and shoulders above anything the competition puts out...

vzdude

I don't know, but on mine, anytime the a/c is on, or temps are anything above 80, the fan runs hard. Very loud. I almost can't hear the turbo above it. It has no problem keeping up with it or anything, I never have run hot. However, I have a friend that works for Cummins, ( as a matter of fact his office is right next to the guy that designed the 5.9 ) and he has said that it takes around 30 hp to run the fan! I think that may have included the a/c compressor as well, but either way, an electric fan would be much more efficient in my opinion. Also cheaper to replace as the fan clutch on my truck is almost 300 bucks.

04ctd

there are several threads on this , a few years old

the problem is CFM - look how steep the pitch is on the stock blades, IOT move enough air, you need that style fan, and that takes 30hp to turn it.

there are some fans out there that will do the CFM - but they aren't cheap, and they draw heavy power. and they are BIG

you guys over analyze everything on these trucks. there is an adjustable rheostat for $17 at Advance.

you put the end in your radiator hose (or attach to radaitor with provided zip ties)

and adjust the set screw for the fan to run when you want it.

try this, then post back up, and i will tell you why it is overheating. there's a trick to electric fans


i don't think the fan runs when the engine is cool enough to affect warm up, that's what the clutch is for. i thought the clutch was affected by engine heat, and only engaged when engine temp was above XX degrees.

HOV

Seriously? There must be something wrong with your cooling system if the fan is running just because of 80* air temps and A/C.

The fan is definitely a power sucker... one of the reasons I got rid of my Duracrap. That fan would never shut off.

I've run my A/C, towed heavy in summer, and generally run my truck pretty hard and the fan has never come on. My coolant temp goes up to about 208 when working hard, then right back down just from regular old air flow over it at speed.

vzdude

What is the trick? I would rather it be explained to me why I am wrong in my thinking than to spend a couple of bucks to find out the hard way. I am not right in many cases , and I admit when I'm wrong. So please, lets discuss this further. Just thinking out loud today I guess!

Rollin' Smoke

my trucks fan comes on when its about 85 degrees or hotter. it usually when i take off from a light and thats with the truck unloaded. i have a code in my computer P0234 if i remember right. it has something to do with the cooling systems. i will try to get that cleared and see what happens

Spooler

Check you radiator, condensor, or intercooler to see if it is clogged with trash. I have done the electric fan thing on other vehicles. The suckers would run hot in stop and go traffic with the A/C on very easily. On a diesel I wouldn't even think about it. If you pull anything with some weight your gonna run hot and burn it up. That would be one heck of an expensive lesson.

04ctd

a fan is a pump; and say; it pumps air at 45mph

a function of the clutch is to let it "overspeed"

so if you are going 65mph, the fans freewheels at that speed - and "road air" cools the engine.

now if you set electric fans to run, and they flow air at 45mph, and you drive a 65, they will NOT turn faster.

they are basically blocking air flow. the air is not FLOWING thru the radiator, the fans are blocking the flow, and stale air is just sitting in front of the fan.

here's the trick:
you have to REALLY watch your truck close, and note what temperature the "road air" cools the motor too, say, on the open road, your truck stays ~200 degrees

now, you have to set your electric fans to come on ABOVE that temperature,
say 205.

if you set the electric fans BELOW 205 - they will run constantly while you are road speed, and they will BLOCK the flow of air,

and you will overheat any time you drive.

a common mistake is to set electric fans at a LOWER temp to cool the engine, and when you get below the "road temperature" you can't figure it out.

there was ~$50K 66 Chevelle in the Hot Rod Power tour with duct tape over his grill because he could not cure his overheating.

guess what? he had electric fans.

overheating in traffic is another problem. you need to run the fans at lower temps with AC on to compensate. not sure how the ECM does that.
i know the old IROC's had 2 fans, and one ran any time the AC was on, as far as i could tell.

you remember the old gas car's had a solenoid on the carb, that kicked up a High Idle when the AC was on?
i would think the IROC one fan would be on that circuit, some how.

somebody jump in here if i am wrong.

hth?

vzdude

I see your point, and am understanding it. Never really looked at it in that way. Thank you for saving me an expensive experiment! Overthinking may be correct, but just always trying to build a better mousetrap!

CamperAndy

So are the guys that did the mod in Diesel Power wrong???? Electric fans have potential but when they are turning they use the batteries that have to be re charged so the alternator will be doing extra duty. Thus there may not be too much load reduction on the engine.

vzdude

Link that mod if ya would please! I'd like to read more about this.