Electric Fan Conversion*** - Fuel Economy, Hypermiling, EcoModding News and Forum

morpheous71 · 01-19-2011, 10:10 PM

Well not really, I like the idea of using an electric fan over the mechanical one, at least I'd like to test it out and see if the results are positive. Just so happens, I drive 2002 Jeep Liberty, which has both installed from the factory already, as far as I'm told the mechanical one only comes on when the electric one cannot handle the heat, forget what temp. that is. I was checking these out and I cannot figure out how to disengage the mecahnical since it all seems to be running on one large serpentine belt which is connected to a whole bunch a things. If I took the mechanical fan right out then the belt is not going to work anymore. Any ideas guys/gals. Before you ask I am certain there are two fans in there I saw them myself, I guess it was offered as part of the tow package from jeep.

t vago · 01-19-2011, 10:29 PM

You need to use a strap wrench to keep your water pump pulley from moving, then use a large crescent wrench on the nut holding the mechanical fan to your water pump pulley. It actually comes off pretty easily, and no re-routing of serpentine belts is necessary.

Your electric fan comes on at about 210 F, assuming that Chrysler programmed your engine computer with the same setting as mine.

morpheous71 · 01-19-2011, 10:40 PM

Thanks. This is what I do not understand though. If I just take off the fan, then the motor that runs it is still connected to the engine, so is this still not loading up the engine. It seems that the removal of just the fan, which usually is not running anyway is not enough??

Frank Lee · 01-19-2011, 10:45 PM

Quote:

Originally Posted by morpheous71

Thanks. This is what I do not understand though. If I just take off the fan, then the motor that runs it is still connected to the engine, so is this still not loading up the engine. It seems that the removal of just the fan, which usually is not running anyway is not enough??

Ummmm... what?

Leave the electric fan alone and remove the mechanical one. Period.

Clev · 01-20-2011, 12:48 AM

Is it me, or does having both an electric and mechanical fan in this day and age seem like an awful kludge implemented to bandage over some hideous design flaw?

vacationtime247 · 01-20-2011, 01:27 AM

Quote:

Originally Posted by Clev

Is it me, or does having both an electric and mechanical fan in this day and age seem like an awful kludge implemented to bandage over some hideous design flaw?

Let's face it, people are stupid. They'll drive their cars with the temp gauge pegged in the red. Electric fans go out, relays go bad and fuses blow. Dual fans are a fail safe to prevent over heating causing significant damage.

Should be able to remove the mechanical fan and still run the serpentine belt normally. Also, how much of the radiator does the factory electric fan cover? Wonder if the electric fan has the capacity to adequately cool the engine without the mechanical. Aftermarket electric fans are farely cheap and easy to install. They'll quickly pay for themselves.
VT247

Clev · 01-20-2011, 01:32 AM

Quote:

Originally Posted by vacationtime247

Let's face it, people are stupid. They'll drive their cars with the temp gauge pegged in the red. Electric fans go out, relays go bad and fuses blow. Dual fans are a fail safe to prevent over heating causing significant damage.

Right, but if your electric fan fails, you're least at risk when traveling at 65 mph and most at risk when crawling through traffic--a time when a mechanical fan is the least useful.

If they wanted to go with redundancy, they should have put in a second electric on its own circuit.

t vago · 01-20-2011, 05:34 AM

The mechanical fan was included in case the OP wanted to go tow something. The electric fan was included primarily for air conditioning, and only was given the secondary job of backup cooling in case the primary fan didn't do the job, for some reason.

I replaced the wimpy little electric fan with a huge Jeep Grand Cherokee 19 inch electric fan. It sounds like a jet engine when it's on. If needed, I can still install my mechanical fan, should I have the urge to haul or tow something heavy.

Clev · 01-20-2011, 10:58 AM

Quote:

Originally Posted by t vago

The mechanical fan was included in case the OP wanted to go tow something.

Again, meaning that you have to keep the revs up, wasting fuel, if you want to tow something, to keep the fan spinning. And I'm not sure if I agree with the failure argument either. I've had many mechanical fan clutches fail, but only one electric fan fail. (And that was actually because the plastic fan came loose from the motor shaft, not any kind of failure of the motor itself.)

brucepick · 01-20-2011, 04:53 PM

I see from Libby's page that it/she has a ScanGauge.
My ScanGauge (on a Civic) will show engine temp from the computer. Very helpful information if you're going to mod the cooling system.

My ScanGauge shows engine temp as ºFWT. Fahrenheit water temperature. Run Libby with the SG showing engine temp for a week or whatever so you get a good idea of what temperatures the car normally runs at. That gives you a basis of comparison after you do your mods.