Just took it for a test drive. Did a little uphill dropped to 4th and hit 80 <img src="/forums/images/graemlins/kewl.gif" alt="" /> Never got above half. Acutally, driving around town it started dropping below normal. I had to turn it off for a while.

Install took about 4 hours. And thats including figuring it out as I went.

I did some minimal modifications to the shourd to make it fit a bit more snug. The fan shroud was a bit bigger than my 3core rad.

For wiring I used the NAPA relay ST85. Its a 75A relay with 4 ports, power in/out, and switched on/ground. I used an inline fuse holder with a 30A autobreaker. 10AWG line for power and ground, 14AWG line for switch.

It seems to work alright with the stock alternator. It did kill the engine when I started the first time because I've made sooo may mods to the engine I really don't have any idle power. So instead of 900 idle its about 1100.

There was some "seatofthepants" gains. It felt really good uphill.

I'm going to keep the stock fan in the truck with me for a while. Just to make sure everything holds. I did not install the diode yet. I understand how it works but hooking it up seems to be a bit confusing...

I should solder it where to where?

Anyway, if you have any questions or comments, I'd be happy to answer. I should have a complete writeup with pictures done in a week or so. I need to get my digi back from my parents in Phoenix.

All in all, it is a VERY simple mod. I can't belive I didn't do it sooner. heh

Josh

I've wondered about that mod for a while. Hope it continues to work <img src="/forums/images/graemlins/smile.gif" alt="" /> You said it gave ya "a good seat of the pants" feel going uphill. YOu then said you're keeping the stock fan in for a while? I'm assuming you put the stock fan BACK in after testing the electric one <img src="/forums/images/graemlins/shocked.gif" alt="" />
Only thing that has kept me from trying that mod is that I was told the "electrical load bogs down the engine just as much as the stock fan". Notice or feel anything when the thermo kicked the fan on??
I still would like to try it sometime. Did ya select the Taurus fan for fit purposes?.....or was it a freebe etc...
Have ta ask ya more about the whole diode thing...not real schooled on electronics.. etc.

Thanks,
shaggy

Nope I'm leaving the electric fan on for good. The electrical bog is nothing compared to the fan.

Its kinda funny. I drove to work and back last night, and never even turned on the fan. Makes me think how badly the fan is even needed... I prolly won't even use the fan all winter... <img src="/forums/images/graemlins/kewl.gif" alt="" />

I used to taurus fan because it is very powerfull and fits quite nicely.

Hopefully someone will be able to clear up the whole diode thing for me. I haven't a clue where to put it. The diagrams online show it connecting to both sides of the fan motor.

So how do I splice in a diode in the middle of 2 wires, one of them being hot? Maybe I can connect it to the positive wire near the relay and then just ground it... Nope still confused...

I'm gonna take a wild guess that the diode is used to shunt inductance from the fan motor (motors are inductive, and can create reverse voltage as the magnetic field collapses).

*IF* that is the case, the cathode goes to positive. Oh, gee, Bill, that helps a lot. Well, the cathode is marked by the band on the diode, the anode is the tail of the arrow in the following symbol:

Ground.....Diode.....+12VDC

(-) -->|-- (+)

If you put the diode in backwards, it will flow BOKU current for a very brief period of time, then it lets out the magic smoke that made it work. If you put it in properly, it will shunt any reverse voltage induction over about .7V.

Caveat emptor on using my advice, which is based on guesses, assumptions, and lately has been evidencing some critical omissions... <img src="/forums/images/graemlins/rolleyes.gif" alt="" /> <img src="/forums/images/graemlins/drunk.gif" alt="" />

I notice the battery/alternator gauge dips down briefly when the fan turns on. The load from the alternator can be significant, but you also have to remember that the fan might not be on all the time.

If you can, mount the diode across the power connections on the fan motor. The arrow on the diode should point towards the +12V coming from the relay, and the other side goes to the neg which should be going to ground. If that is inconvenient, just hook up the diode to the +12V relay contact that feeds the fan with the arrow on the diode pointing towards that contact and attach the other end to a convenient ground. If the +12V side of the diode has its lead exposed you might want to wrap tape around it or use heat shrink so it doesn't accidentally get shorted to something.

Thankyou Gary.

That is the exact answer I was looking for. Would it be best to disasemble the fan and put it inside? or should I make a slit in the wire, insert the end of the diode, soider then tape up and repeat for the other? I'm surprised that the fan does not have a diode inside if it is needed to keep the thing from going up... I would be far easier to just sodier on a endpeice and connect it to the relay. But I will see what looks best.

Josh

I'm glad to hear it's working out for you Josh. Just one qestion though, why? You are a smart guy and therefore of course understand that energy cannot be created or destroyed, but can only change form. If you are moving X amount of air, depending of course on the efficiency of the blade design, it will require Y amount of energy. Period. You cannont replace direct mechanical energy with electrical, which incurs greater losses through the <75% efficient conversion from mech-elect.-mech (alternator-motor-fan) than it would through the highly efficient and reliable stock clutch type fan. Maybe your clutch was shot, mine kicks off from a cold start in about 30 secs, and I don't hear it roaring again ever here in Iceland. Even there in the desert it should operate the same way, basically freewheeling at normal operating temps. I think the parasitic losses from mechanical fans are mostly fiction created to sell black magic junk. I have heard great stuff about OEM type fans like the Taurus one you have though, If I ever had a need for an electric you would see me at the pick and pull :-) Stay cool <img src="/forums/images/graemlins/lol.gif" alt="" />

I just get curious and like to try stuff.

This is something interesting I found... I drove from Flagstaff, AZ to Phoenix, AZ about 130miles with the fan off. Never did it get above op temp. Then I drove around Phoenix. I went about 20 miles stop and go traffic in Phoenix and never used the fan. I turned it on once to make sure I didn't already have it on. So about the Law of Conservation of Energy, if you don't use energy, well horray! <img src="/forums/images/graemlins/cheers.gif" alt="" />

I'm sure I'll use it going back up the hills, but maybe not. There is a ~2000ft climb between Verde Valley and Camp Verde. Hard uphill, slow trucks on the side of the road, about 10 miles, and never used the fan. I watched my gauge more than the road... <img src="/forums/images/graemlins/rolleyes.gif" alt="" /> Never got above half.

Now I do have a 3core radiator and a 22RET thermostat(180deg). And that may have something to do with it. I don't think I'll even use the fan all winter in Flagstaff, sounds like I'll be getting better gasmileage in Flag <img src="/forums/images/graemlins/kewl.gif" alt="" />

Take care

Josh

Arbitrary -
A caution: dont always believe what the Toyota gauge tells you. I installed an actual temp gauge and it tells a much different story than the Toy gauge.