yes fans are great, you can feel them kick on, but i know that on highway cruising my truck jumps out of overdrive 75% less times on hills and such then it used to

 

Hi

Some toughts ...

I think you just contradicted yourself. A fan that appears identical, may not be. A $60 fan IS junk. A fan from the wrecker - you just need to ensure it is not damaged and/or has some life left in it.

Yeah - MAD's kit does that with an FR-86. IMHO, Two pullers, mounted on a plate, which in turn mounts on the rad supports, works well. A separater between the fans prevents the fans driving each other.

Two fans for redundancy is preferred ( with 2 controllers). A push / pull arrangment is risky; if the fans are not perfectly matched, one WILL conflict with the other. Also, the same model fan usually has different performance in a pull versus a push configuration.

A relay is mandatory; too much current involved. UNLESS, the controller has one suitable already embedded, or the solid state ones ( e.g. SPAL , with soft-start) include a semiconductor switch rated appropriately. These also have built in suppression for reverse voltage protection from any fan EMF.

If you go this route, choose high quality components only and wire it robustly.
Going cheap and/or using poor installation methods ... not a good idea. This is your daily-driver's COOLING system we are talking about here. If you don't follow through on good design and use best-practice install methods, don't do it. Stay with the stock mech fan.

IMHO ... okay?

Cheers
Bubba

. <---- my compliant sig lol

 

MGD, you have a point of course, appearances aren't everything but what I meant was, if the $400 kit fan is identical to the $60 fan - ball bearings vs ball bearings etc and I'm satisfied the quality is equal, I'll go with the $60 fan, I don't mind doing a little of my own fabricating (and it sounds like a lot of the mounting kits are less than good) and I'm quite experienced with making wiring harnesses etc so that wouldn't be a problem for me - two relays in parallel is an interesting idea, I had actually been considering using one of the disused fuse & relay spots in the factory under the hood fuse/relay box if it's not too had to add the wiring/contacts if necessary, that'd certainly be the neatest - as for the two-fan idea, if I use smaller push-pull fans and offset them, there'd be less problem with interference with each other, and, as I mentioned, if the forward one is mounted off the radiator, it'd be more like the emulation of the natural flow of air at speed....I may or may not go with the two fans, I may start with one and see how I go, I may consider an arrangement where both will never run together (if I go for higher capacity fans)

As to the question of power gains, I don't know how accurate the figures are, Malexander, but consider these factors - at speed, as Patman observed, is where they really shine, as at a speed where you have decent airflow, there's little need for a fan, yet a belt-driven fan will be spinning for all it's worth, perhaps even over-cooling the engine, robbing it of power and economy, as well as providing a significant drag on the engine while it turns the fan - an efan will sit there and draw no power, and the alternator will be under normal load and the engine will run more freely and economically, not turning a redundant fan.

Clutch fans are somewhat better, but will still turn and produce drag, even when disengaged, they just don't turn as much.

At idle, the efan again does a better job, because the fan runs at full speed - a belt driven fan will just be ticking over and therefore not producing the airflow it needs...so the clutch will remain engaged - sure, the efan will draw on the battery/alternator, but will cycle on and off since it cools more effectively (and it's not undesirable to have the fan run without the ignition provided you are mindful of the fact it can kick in without warning, since the engine's temperature will spike when you turn it off, since it's hot, and not being cooled, I've heard it argued this is quite damaging)

 

Galaxy, the same thing happened to me, although my fuse blew before the entire fuse holder melted. I noticed that my Ac was not as cold while sitting waiting for a person, when I checked the problem the hi temperature fan was not operating. The fuse was burnt out and melted in the holder. I believe what happens is that during the process of setting the fan temperatures you remove the fuses several times, doing this spreads the terminals that contact the fuse blade and makes a high resistance area that creates heat. i took flat bladed pliers and crimped the terminals before installing new fuses, I did both fuse holders and have not had a single problem since. Mine have been OK for the past three years. Every once in a while I still check to see if both are working.