Electric Fan

[delicat]

I think you'd only use the A/C fan without the compressor, that way you'd have 2 fans instead of one to move more air. That's how I understood the mod anyway...

[Modsqwad]

I think you'd only use the A/C fan without the compressor, that way you'd have 2 fans instead of one to move more air. That's how I understood the mod anyway...

I am about to go out and do that exact mod right now. All I have to do is bypass the fan relay so it runs continuous with the key on
and when I hit a big hill turn off the ac. The fan will keep running and Bob's you uncle! I'll report back on how it worked after this
trip.
Andy Wilson

[Modsqwad]

I think you'd only use the A/C fan without the compressor, that way you'd have 2 fans instead of one to move more air. That's how I understood the mod anyway...

I am about to go out and do that exact mod right now. All I have to do is bypass the fan relay so it runs continuous with the key on
and when I hit a big hill turn off the ac. The fan will keep running and Bob's you uncle! I'll report back on how it worked after this
trip.
Andy Wilson

Ok that was fast (really a 10 minute job) however not quite as easy as I had hoped. The main power to the fan relay is not
switched with the key (murphy's law). I wound up having to find a key switched wire next door (Wiper motor) and use
it to switch the relay. 2 minuets and a jumper and Bob's you uncle. I think in the long term I will install a manual switch
somewhere to have complete control over it but for the short term I get my cake (engine fan) and eat it too (electric fan).
That should get me through the desert ok (I hope).
Andy Wilson
Sayulita Nay. Mx.

[loki]

Let me get this straight. I'm going to turn on the AC, along with the mech. fan (which I have no control over), alternator (when it is required). And you think that all of that isn't a lot to run? I would rather have the alternator running only, to limit the amount of drag on the engine. Now, I don't have a overheating problem, just a lack of power to operate all of the things that were suggested to keep my vehicle in its operating temperature. Cheers

the thing is the amount of drag the alternator has changes depending on the load on it so it's not that straight forward. the energy has to come from somewhere, you could put solar panels on the roof and run the fan with that :)

[jfpdelica]

Sorry for me not understanding this quite yet. If you have three belts operating at the same time, (alternator,mechanical fan, AC) would that not mean that there is a huge lose of power when compared to a single alternator of larger size with a electric fan? Maybe my logic has failed me? Jeff 8)

[loki]

Sorry for me not understanding this quite yet. If you have three belts operating at the same time, (alternator,mechanical fan, AC) would that not mean that there is a huge lose of power when compared to a single alternator of larger size with a electric fan? Maybe my logic has failed me? Jeff 8)

the number of belts and of things running off of them is really pretty irrelevant, Drag on the engine if what is important. an alternators drag will change with the load on it (it's not free energy :)). I'm not saying one is more efficient than the other just that it isn't cut and dried, so many variables, the draw of the fan and the wiring to it, the drag of the clutch fan, the condition of the fans clutch.....

[Modsqwad]

No matter how you cut it the engine is going to have to produce the power needed to move air through the rad. If you remove your
engine driven fan you will remove the energy required to drive it but will increase the load on the charging system at least as much
to produce enough power to drive the electric fan you replace it with. There is no such thing as a free lunch when it comes to energy.
Its like exchanging dollars for pesos you never get the same amount back there are always losses whenever you change from one
type of energy to another. IE engine to alternator to electric motor back to fan. Sad but true.
Andy Wilson

[jessef]

If you remove your engine driven fan you will remove the energy required to drive it but will increase the load on the charging system at least as much to produce enough power to drive the electric fan you replace it with.n

the draw off the Taurus electric fan was very minimal. Definitely not as much of a draw when compared to the mechanical pull of the fan clutch.

[Modsqwad]

If you remove your engine driven fan you will remove the energy required to drive it but will increase the load on the charging system at least as much to produce enough power to drive the electric fan you replace it with.n

the draw off the Taurus electric fan was very minimal. Definitely not as much of a draw when compared to the mechanical pull of the fan clutch.

An interesting question in efficiency ie engine driven fan HP/CFM against electric Amps/CFM without data its hard to pin down.
Perhaps the electric fan could be more efficient I certainly don't claim to have the answers but still think energy conversion will always have some cost. Also this alternator is hard to get and I want to baby it. How well does your electric fan work?
Andy

[RaddCruisers]

Electrics are FAR less efficient than engine driven fans - they simply cannot move anywhere near the same amount of air as an engine driven unit will.

I disagree.

The stock clutch fan on my 2.5 was like comparing a little 2AA battery fan and the Taurus electric fan being an industrial blower.

When I went into a few water crossings, I'm able to turn it off completely so it won't soak the engine compartment, get water in everywhere and if by any chance I end up getting stuck in the water with the engine running I'll have less danger to hydrolock it although you'd have to really bury the thing in water with the engine running in my opinion before this was an issue since the intake is away from the fan.

I prefer the electric. You're driving anyways, so the battery/alt is powering/charging it. It's lighter and the obvious is that there are no mechanical parts. Less drag/belts, etc...

Advantages and disadvantages I guess.

I'm putting on on my L400 as well.

If you feel that your engine fan is wimpy, then the clutch is not engaged. It will only engage when there is sufficient heat blowing over it from a hot rad - so the rad must be working properly, along with the rest of the cooling system. These fans can move a lot of air when the clutch is fully engaged.

Clutch fans and water crossings are not a problem, they disengage or slip. In any case, the fan is far enough from the radiator to prevent any damage from the fan pulling into the rad (the real reason for this in most cases). And, when you're doing a water crossing, you should be going quite slowly - so there should be little issue with the fan.

Hydrolock - is caused by water entering in through the intake in an amount that exceeds the engine's ability to pass the water (which isn't very much!). If you're in water that deep, you're probably piloting the wrong kind of vehicle. It's good that you noticed the air intake was far away from the engine...

Water on a diesel... no problem, there's no distributor to soak, or plug wires for that matter.... it will not stall due to ignition related problems. There are no more or less issues with a mechanical fan versus an electric one in this instance. Alternators, mind you, don't really like being submerged all that much.

No mechanical parts? Huh? What does that save you? It's an electric motor... It's prone to failure just like anything else electrical/mechanical. In fact, more electric fans fail than engine driven units.

I've got lots of real world experience under my belt on these issues (off-roading, mechanical repair) and many of your points are, well, pointless. Electrics do become of use in gasoline powered vehicles that are under high load, moving slowly, and working at low RPM such as rock crawling in the Arizona desert (which means they're generating lots of heat). A diesel working at low RPM generates considerably less heat than a gasoline-powered unit.

Again, if you're cooling system is working as intended from the factory, you should have no problems keeping things cool under these conditions.

To answer another post: 50C heat going up Richter pass with a loaded van and trailer? Then back off the throttle a little, keep the revs up a bit by backing off a gear or two, and take it easy on your vehicle.


~John

[jessef]

I agree with you John about the stock fan being adequate. I replaced mine with the electric fan because my clutch fan was toast and the Taurus fan was cheaper than a new clutch fan.

This was on my Pajero so a little different than the l300.

I echo your comment about backing off the throttle uphill. That's why a pyro gauge would be a good thing to have.