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You know your Jeep has an electric fan right?

Try removing your mechanical fan and let us know how it goes. Be the guinea pig!

True there is an electric fan but it only comes on to cool the A/C condenser or once the engine reaches a point it kicks in to help aid in cooling. It's not a stand alone electric cooling fan for the engine as my diesel mechanic was explaining. That's why I was asking if anyone hooked an actual fan rated for the cfm of our trucks. The fan we have is adequate, but like most on here, I think we can do better.

3. Cooling fan system. The mechanical fan has very high parasitics and can reduce fuel economy by up to 2 mpg depending on driving style. Running without the mechanical fan is not feasible if the vehicle is loaded or pulling a trailer, the heat load is too great. The electric fan on the KJ CRD is a pusher style and used mainly for cooling the condenser for AC performance. A pusher fan is not very efficient as compared to a puller fan. A pusher fan is located in front of the cooling system and a puller fan is located just behind the cooling system. Ideally, one could remove both fans and install an aftermarket electric puller fan and it would suffice for most situations, minus a heavy trailer in harsh ambient conditions. We are not aware of any electric fan that can pull 5000 cfm (cubic feet minute) of air through the cooling stack. The condenser, CAC and radiator have too much pressure drop for any fan less than about 800 watts of power.

Pablo, did you eventually go with the electric?
I can't see how a good high flow electric would be bad. There isn't a performance car sold today i.e. Viper, Porsche, and Ferrari that comes with a mechanical fan on it.
I would think with the proper cfm rated fan that cooling would be as good as factory without the parasitic loss.

Author:	NJCRD [ Mon Jun 29, 2009 1:58 pm ]
Post subject:	Electric Fan?
Has anyone installed an after market electric fan on their CRD? If so, which make and model? How was install? Have you increased fuel mileage? My friend picked up 4mpg on his Chevy S-10 just with the electric fan. I know on a gas motor the parasitic loss of the factory fans robs some HP, but does the diesel make enough to easily compensate for this? Looking forward to hearing from the plethora of information that comes from this board.

Author:	CATCRD [ Mon Jun 29, 2009 9:41 pm ]
Post subject:
You know your Jeep has an electric fan right? Try removing your mechanical fan and let us know how it goes. Be the guinea pig!

Author:	BlackLibertyCRD [ Mon Jun 29, 2009 11:40 pm ]
Post subject:
CATCRD wrote: You know your Jeep has an electric fan right? Try removing your mechanical fan and let us know how it goes. Be the guinea pig! Oh no, not I. I do know that my electric fan does come on when running the A/C and just coming off the pike on a hot day. Must be very warm under the hood.

Author:	flash7210 [ Tue Jun 30, 2009 3:56 pm ]
Post subject:
Hmmm... But which fan comes on first? The electric or engine driven? When driving a D-Max or P-Stroke you can hear the roar when the engine driven fan kicks on. (its the only fan they have) I never hear that with the CRD. Maybe it just never gets that hot? But yes, the electric fan always comes on when AC is on.

Author:	NJCRD [ Wed Jul 01, 2009 9:27 am ]
Post subject:
True there is an electric fan but it only comes on to cool the A/C condenser or once the engine reaches a point it kicks in to help aid in cooling. It's not a stand alone electric cooling fan for the engine as my diesel mechanic was explaining. That's why I was asking if anyone hooked an actual fan rated for the cfm of our trucks. The fan we have is adequate, but like most on here, I think we can do better.

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Author:	danoid [ Wed Jul 01, 2009 9:40 pm ]
Post subject:
Other than 'morning sickness' (the fan roar when the hydraulic clutch doesn't fully unlock on the first acceleration of the day) my belt fan only comes on when towing. It makes a good roar at 65 mph when it's on, and the temp needle starts moving away from the red zone promptly. Then it turns off, the needle starts creeping up and 20 minutes later, it's on again.

Author:	CATCRD [ Thu Jul 02, 2009 10:45 am ]
Post subject:
NJCRD wrote: True there is an electric fan but it only comes on to cool the A/C condenser or once the engine reaches a point it kicks in to help aid in cooling. It's not a stand alone electric cooling fan for the engine as my diesel mechanic was explaining. That's why I was asking if anyone hooked an actual fan rated for the cfm of our trucks. The fan we have is adequate, but like most on here, I think we can do better. I would bet that there is a limit of coolant temperature that the ECU will turn on the electric fan regardless of the A/C status, like you said, and if you're not towing or driving in AZ, it may not be a dangerous level. Try removing your mechanical fan and see what your coolant temp reaches in daily driving and see if it has an effect on mpg. If so, free mod.

Author:	Pablo [ Fri Jul 03, 2009 12:40 am ]
Post subject:
See here for everything you never wanted to know about the electric fan kerfunkle: http://www.lostjeeps.com/forum/phpBB3/vie ... p?p=318142

Author:	NJCRD [ Mon Jul 06, 2009 11:09 am ]
Post subject:
Pablo, did you eventually go with the electric? I can't see how a good high flow electric would be bad. There isn't a performance car sold today i.e. Viper, Porsche, and Ferrari that comes with a mechanical fan on it. I would think with the proper cfm rated fan that cooling would be as good as factory without the parasitic loss.

Author:	JL Rockies [ Mon Jul 06, 2009 1:23 pm ]
Post subject:
I still think you would deal with parasitic loss since the load will now be on the charging system. I think those fans take a decent amount of current to stay running.

Author:	flash7210 [ Tue Jul 07, 2009 12:34 pm ]
Post subject:
I've found that electric fans like our typically draw 6-10 amps. Thats a pretty heavy load. edit: Most FWD cars have two of these fans making total load ~20 amps. It would seem that power loss from the mech fan is kind of a mute point. I mean, its only active for short periods of time. In most cases only when really really hot, or when pulling a heavy load. In either case, the loss of a few HP from the fan is nothing compared to the loss from higher IAT. And if you are towing, I'd be more concerned about getting there safely without overheating then trying to squeeze every last horse out of it.

Author:	Scott Langohr [ Wed Jul 08, 2009 9:04 am ]
Post subject:	Cooling fan operational question
On my truck, the electric fan comes on as soon as I turn the key to the on position. I pause at this point in the startup routine to allow the fuel pump a little time to clear air from the fuel head if any has accumulated and allow the glow plugs to do their thing. It may not be necessary but I am in the habit to do so. I did not think to much about it until I am reading this stuff and I am thinking that it is not normal for the electric fan to come on in this fashion. I currently have the truck at the stealership for a #4 glow plug replacement (code 1267)and he called me up and said I need a new cooling fan motor and it would be 670.00 and take a couple of days to get it. I told him to forget it. I looked it up at Mopar Parts America and the whole assembly was 55.00. My question is; Since the fan runs all the time (I assume it does since I can't hear it once the engine starts and have not bothered to look at it after it is running) how can the fan motor be bad unless the control that turns it on and off is incorporated in the motor. I would think that there would be a temperature sensor that would do that or it is getting a signal from the ECM to turn on. In any case, I am not going to spend 670.00 to get it to shut off. I have never had any overheating problem and it warms up quickly to a tick under center on the guage and stays there. Am I going to have to replace it to get it to function properly and is it a big job to replace it if I need to?

Author:	NJCRD [ Wed Jul 08, 2009 9:28 am ]
Post subject:
The electric fan should not come on until the engine is hot. The fan is for the A/C condenser. If it comes on the second you hit the ignition, then something is not right. Maybe a fuse is blown or it's miswired?

Author:	GreenDieselEngineering [ Wed Jul 08, 2009 1:55 pm ]
Post subject:
Regarding the electric fan in front of the cooling stack, we though it might be advantageous to post up some info about how and when it will come on based on our experience of playing with different settings in the mapping: With the A/C turned off, the electric fan will turn on at low speed at 96.5C and high speed at 107C. With A/C turned on, fan control can be selected depending on ambient temp: -Ambient above 35C, low speed will engage: above 72C engine temp, less than 60mph and high speed above 108C any speed -Ambient below 35C, low speed: above 96.5C engine temp, less than 60mph; high speed: above 108C any speed A/C head pressure - medium pressures, low speed fan; high pressures, high speed fan Trans oil temps - low speed above 90C, high speed above 113C Hopefully this will help in understanding when/why/how it can turn on, or if it is on already and it shouldn't be some information to check and see if something is amiss.

Author:	CRD Joe [ Wed Jul 08, 2009 6:16 pm ]
Post subject:
Just one Flex-A-Lite electric fan model. Model 280 Height 17" Width 31-7/8" Depth 4-1/2" CFM 3300-5500 Amp Draw 12-28

Author:	Turbo Tim [ Wed Jul 08, 2009 9:16 pm ]
Post subject:
Sorry Joe, 100% BS. Airflow-Cu. Ft./Min. at 0º Static Pressure - 3300-5500 http://www.flex-a-lite.com/auto/html/monster-electric.html Unfortunately we don’t live in a fairy-tale world were you only need 0* static pressure. If you use a professional air flow meter (like Alinor, Extech, Kanomax, etc), compare the air flow against the mechanical to the electric. Air flow without pressure = 0. I have done many tests and unless you have at least 5 inches of water column pressure, it doesn’t move zip. For example, we did a test on an old Corvair sandrail 140 HP engine using electric fan(s). Long story short, that fan with a spool-up ratio of 1.6 would suck about 12 HP off the engine, push almost 6000 cfm of air with about 12 inches of water column pressure. We tried it using electric fans and only got to 0.5 inches of pressure and quickly overheated. We ended up using a jet starter motor, drawing about 80 amps, to push enough air that was almost 75% of what the mechanical fan did. Long story short, you don’t get something for nothing. No matter how you cut the cake, it’s going to take horsepower to move the amount of air required. I would love for someone to take CFM@pressure readings first, then do the electric and post. Not trying to flame ya. The physics of moving air just doesn't add up.

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Author:	CRD Joe [ Wed Jul 08, 2009 2:42 pm ]
Post subject:
Seems to me Flex-a-lite would make an electric fan capable of replacing the engine driven jobber on our CRD's.

Author:	NJCRD [ Wed Jul 08, 2009 4:13 pm ]
Post subject:
A dodge viper that makes over 500 hp and 500 lb ft of tq uses a 4000cfm electric fan. High performance v10. I'm thinking that 4000cfm should be enough. If anyone knows what our cfm rating should be please advise.

Author:	linewarbr [ Wed Jul 08, 2009 5:00 pm ]
Post subject:
In their "Food for Thought" thread, GDE suggests 5000 CFM with 800 watts of power. Quote: 3. Cooling fan system. The mechanical fan has very high parasitics and can reduce fuel economy by up to 2 mpg depending on driving style. Running without the mechanical fan is not feasible if the vehicle is loaded or pulling a trailer, the heat load is too great. The electric fan on the KJ CRD is a pusher style and used mainly for cooling the condenser for AC performance. A pusher fan is not very efficient as compared to a puller fan. A pusher fan is located in front of the cooling system and a puller fan is located just behind the cooling system. Ideally, one could remove both fans and install an aftermarket electric puller fan and it would suffice for most situations, minus a heavy trailer in harsh ambient conditions. We are not aware of any electric fan that can pull 5000 cfm (cubic feet minute) of air through the cooling stack. The condenser, CAC and radiator have too much pressure drop for any fan less than about 800 watts of power.

Author:	Pablo [ Wed Jul 08, 2009 5:43 pm ]
Post subject:
NJCRD wrote: Pablo, did you eventually go with the electric? I can't see how a good high flow electric would be bad. There isn't a performance car sold today i.e. Viper, Porsche, and Ferrari that comes with a mechanical fan on it. I would think with the proper cfm rated fan that cooling would be as good as factory without the parasitic loss. No. It would not work in AZ. My mechanical comes on whenever I stop moving forward when it is hot here (106 today, Saturday is 115). I wanted it primarily for the ability to turn it off when crossing water. The other link talks about a electronically controlled magnetic clutch on a mechanical fan... (or something like that)... that is used on the GM SUV's. Unfortunately, it did not appear to be a very durable solution in the GM vehicles using it.