96 tacoma 3.4 Looking to do a electric fan swap and instead of buying over priced flexlite fan I was looking into fan setup off another vehicle i heard of people using ford tauras fans but i havent seem to find what year car and what engine size to look for. If anyone can give me some insight on what is the best setup to get I would be grateful.
I also heard when the dual fans come on,say when the a/c kicks in that the load the fans put on the alternator is quite a bit. I was wondering would the load be enough to decrease fuel economy and if so if i was to run a override switch in the cab so i can turn the fans off when cruising 70 mph on the hwy would the forced air going into the radiator be more then what the fan would put out and still keep everything cool. I am sure the mpg difference would not be a lot but a 200 mile non non stop stop every weekend would probally add up

 

The best setup is the fan that comes with your truck.
If you install an electric fan you will also install a thermostat control for it so it probably won't come on on the highway unless it needs to.
There's lots of info on the taurus fan in the 2cnd gen 4runner section.

 

dont the fans come on regardless when the a/c is swiched on

 

There are three options to wire the electric fan:
1. the fan turns on when the the coolant temp reaches a certain temperature. this is the standard way of wiring the electric fan
2. the fan turns on as above and also when the ac compressor clutch engages. you'll need addtl relays for this option.
3. only one fan turns on when the ac compressor clutch engages while the coolant temp is below the set temperature.

 

I was just reading about electric fans in an "insiders" magazine that I get and have been considering putting them in my 83 so this is what I can tell you...

1) You will need about 1 amp for every 10CFM of air flow. You will need at least 300CFM, so make that 30amps! I think the Taco alternator puts out 90amps or so (the 83's is 55amps) but its going to be more the battery then the alternator that takes the load (see #4) so you may want a battery upgrade with the highest RC you can get in the group size of battery.
2) I was looking at getting my fan from the wreckers out of a...TOYOTA! Hey why not its familiar stuff.
3) Most thermostatic switches will switch at 180 degrees...get it from that Toyota at the wreckers too! You may need an over-ride switch as it may come on at highway speeds. I haven't looked into the switching temperature of a factory Toyota switch, there may be different settings from model to model.
4) Generally the fan will only come on at idle or slow speeds. At highway speeds (I say anything over 25 - 30 mph) there is enough air flow that the fan isn't necessary. We also own a Yaris and I can only re-call hearing the fan come on stopped in traffic in the summer with the A/C on. Further on this, one of my blah, blah, blah stories, my dad and I used to help at a local warplane museum with one of the two flying Lancaster bombers (guess that narrows it down!)...those Packard Merlin's didn't have cooling fans and they really didn't have that big of radiators for 1000hp+ engines...the engines could overheat sitting idling on the runway but once in the air never would, and there are plenty of air cooled aircraft engines. Guess the point here is, it isn't going to need a fan once your moving.
5) Experts, those people who are so arrogant to admit they're ignorant, claim you will in fact get better mileage and more rear wheel horsepower because the fan isn't turning all the time.
6) As far as I can tell the fan doesn't necessarily come on when the A/C is switched on unless the engine is above a certain temperature, which I don't know what it is.

 

And one more point...
6)The factory Toyota thermo switches for the fan are usually normally closed (closed below the set temperature) and you will have to wire the fan through the normally closed power contacts or the fan will run all the time below the set temperature, opposite of what you want. After market switches may be different.

 

Many people use the a mercury villager/Nissan quest fan. It's the same 2 speed motor as the Taurus fans but is 18". I bought one for my 94 runner but with the 3.4 swap and 3 core rad it wasn't gunna fit. I settled on a 16 Volvo fan, again with the same 2 speed motor.

For controlling them, you really want some kind of thermostic switch. For a simple and arguably more reliable setup, you can buy dual temp switches that were available older BMWs, VWs and Saabs. Theres probably a few others out there. I don't know of any dual temp switches as an aftermarket "universal" kind of switch.

You can buy electric fan controllers too. Stray away from the ones with the built in relays and probes that go into the radiator fins. They're very problematic. The only ones I can find that are truly digital are from Painless Performance, Dakota Digital, and Harris Performance Controls (HPC).

The HPC controller was the most appealing to me. It's small, comes with proper connectors, uses a GM temp sensor, supports A/C and a manual switch, and the circuit board is fully potted so it has excellent water resistance. Oh and adjustable. The A/C control also staggers the fans. It will come on low first then high about 2 seconds later. This keeps the high fan from hammering the electrical system every time the compressor cycles on. You can buy just the controller, or a a full kit with relays pre wired for your particular fan setup, the 2 speed fans being one of them. You can also get different size sensors too. Some can even operate, both the controller and the gauge or ecu, which ever you choose. Mine is working perfect, however I've only have had it installed for a a few, yet harsh days. There doesn't seem to be many people using it. I had a hard time finding reviews for it.

Typically the best place for temp sensor is high in the intake. Closer to the outlet the better. Fans should be adjusted to come on low about 10f above thermostat temp. If your stat regularly regulates around 185, the fan should come on about 195. Set it too low, it'll never turn off. Some people use hose adapters for temp sensors. While they work OK, it's just one more place for a leak. Take it with a grain of salt, many people disagree, but I have my sensor located on the radiator outlet so it regulates radiator temperature as it should. It's set to turn on low at 160 high 170. It prevents the the engine from ever getting above normal operating temperature and allows for the fan to still turn off while cruising. Again though, only been installed this way for a few harsh days but it's cold outside. I have yet to see how it holds up stressed in the summer.

For your kill switch question. Yes, you can have a kill switch in the cab. If you plan on doing any deep water crossings it's almost a requirement that you install one just to save your radiator. However, don't kill it on the highway with the A/C on. A/C is very air hungry. If the compressor is running, the condenser is getting hot. Unlike an engine, we don't have a gauge to look at for condenser temperature. There's no way of knowing that the pressure is too high untill it's too late. If your lucky the A/C will get warm and there might be a high side kill switch. If there isn't a switch or it's faulty, it will continue to build pressure until something gives. I've seen some faulty systems reach over 500psi before being able to turn them off, and it's a bit terrifying. Again, if the compressor is running then the fan needs to be running, regardless of vehicle speed.