Ace83

iTrader: (6)

Ok for additional cooling, im planning to put a third fan.. Im planning to tap it on the stock fan wiring so it turns on and off depends on coolant temp or Is it better to do a separate switch and manually turn it on or off? some better ideas?

toyota_scion_tc

Why not put a lower degree thermostat in?

rallying_the_scion

or put the 3rd fan on a relay so you dont overload the fuses and such on the other 2 fans.

Ace83

iTrader: (6)

putting a lower deg thermostat will be pointless at this time since the two fans i have are constantly on during city driving and frequent stops..

putting a relay sounds good but im kinda noob on that.. what type of relay will i need?

toyota_scion_tc

A Bosch 5 pin style will work they are the easiest to wire. pins 85 and 86 are for power and ground. pins 87, 87a, and 30 would be used for the additional power and fan. You will need to test with a multimeter to see which pin to use. I think you would use pin 30 and 87a for switched power. I can't remember. Why not get the Mishimoto radiator?

Ace83

iTrader: (6)

I already have it.. it was a great help until one of my 12" fan died, i replaced it with an 8" 2100cfm fan and it didnt do the job maybe because it pulls air on a lesser surface area, 4 inches lesser than the 12" fan. Now I wanna run a 12" fan again and just leave the 8" fan there..

So Bosch 5 pin 30 amp relay? Would I need a wire to connect to the a/c or thermostat?

rallying_the_scion

nope, splice to the wire to your other fan, run that to the relay to close the contacts, and run the other wire from a power source, battery or what ever, to the relay and from the relay to the power wire on the fan. If i get a chance tommarow ill make a diagram for ya, im working 12s, just ogt off and have a appointment in 6 hrs then to go to work 5 hrs after that.

Ace83

iTrader: (6)

^^ Im kinda lost with that lol.. which is nope? which wire to splice? lol diagram would be better.. I have an idea now on how to do it but im taking suggestions

rallying_the_scion

here ya go, hope this helps!!

Ace83

iTrader: (6)

that's so much better, thanks.. question though, why do I have to wire the new relay to the existing fan's power wire?

rallying_the_scion

use a but splicecut the power wire on the old fan, strip each end add a wire going to the relay, ill make a pic for ya in a bit, got to go into town.

Ace83

iTrader: (6)

yeah but why do I have to tap the power wire of the existing fan when it already have its own power from the stock wiring and relay? isnt that supposed to be tapped on a wire that goes to the thermostat so it will know when to turn on or off?

rallying_the_scion

well, you could tap into the thermostat wire to, depends on what you want to do. I would use the smaller fans power wire cause its next to the other fan, your already working there, and...maybe i think to hard, lol.

as for going on and off, when the thermostat would turn power on to the smaller fan, youd get power to the relay as well, which would close the contacts and allow power from another 12V source to go to your bigger fan.