@all running electric fans!

[s13_rb25det]

hi fellas,

i have an rb25 sitting in my s13 and due to thicker upgraded water radiator and spacing issues, i had to remove the vicious fan that is usually connected to the stock RB engine... now i have purchased 2 electric fans and i am wondering were they get their signal from to turn on/off??? the ECU or fuses/relais??

it would be good if it takes it from the ECU cause i have a PFC pro installed, and i guess that i can then regulate when it switches the fan on/off...

any clue/ideas/suggestions? how did u do it?

thx,

nico

[Joe]

on mine, i have 1 wired to anytime the ignition is on. the other is on a switch i control.

its up to you how you wire it, just make sure you do it the right way, i.e. use relays.

[gawdzilla]

i got the power for mine through the AC power source, which is ign based, through a relay and fused. only downside is it assumes you dont have AC and the AC fans, and the fans cant turn on if theres no ign.

[DrifterTom]

one of mine is wired through ignition and the other is wired off of a factory pressure switch on the lower radiator hose. when the car begins to heat up the fan kicks on until it cools off. it runs with the ignition off as well. kamin's right about using relays.

[Darius]

Alright I'll be the dumba$$ to ask the newb question...how exactly does a relay work different from hardwiring? What purpose does it serve?

[gawdzilla]

think of a relay as an electronically activated switch. it allows things of higher current draw to safely turn on and off. you use your small current signal to activate the relay, and the relay will then allow current to flow to your important stuff- fuel pump, ecu, fans, etc. its a lot safer than physically triggering the high current draw items directly.

[Darius]

Got it. So you hook power to one half of a switch, the other half to a relay, then the relay to ground. When the switch closes the circuit the relay is triggered and opens/closes depending on which type of relay it is, right?

[gawdzilla]

dunno the best way to describe it... try playing w/ this diagram to get an idea...http://electronics.howstuffworks.com/relay1.htm

[bmadd2402]

kinda. most likely you will have four prongs. one goes to the swithch, one power for fan in, one power to the fan, and one to ground. just make sure you fuse the one from the battery. I went a step further and wired two switches: an manual switch and a thermo switch. I just spliced the two wires on the same prong. here is a diagram:http://www.r1200gs.info/howto/relay.html




Modified by bmadd2402 at 3:12 PM 3/2/2006

[cvc9216]

mine are wired to the factory a/c relays with the switched ground wired to a 180* switch

[Yellow4g63]

Fan controler here. Comes on when needed and shuts off when not needed.

[bmadd2402]

kinda. most likely you will have four prongs. one goes to the swithch, one power for fan in, one power to the fan, and one to ground. just make sure you fuse the one from the battery. I went a step further and wired two switches: an manual switch and a thermo switch. I just spliced the two wires on the same prong. here is a diagram: Wiring in the relay

[lyon23]

I connected mine to the factory wire that feeds the oem fan... it has a high and a low, I connected each fan to one of the two connections and it's already goin through the factory relay. you just have to provide a ground to the wire that turns the relays on..I have them with 2 separate switches.. I tried to use one switch to provide ground to both at the same time but they would not come on.

[Wulfgang]

I made a thermo control that reads the coolant temperature from a spare KA engine temp sensor and stages the two fans to come on separately. Fan1 comes on at 90C and goes back off at 80C. Fan2 comes on at 95C and goes back off at 85C. The controller uses the stock relays to switch the fans.

This is sort of a downgraded version of the full proportional control I had planned (but didn't make because I haven't been able to make a good PCB).

[BoostFab]

you can get a thermal controller for radiator uses at your local auto parts store, it will activate by sensing certain coolant temperature. mine was $25 made by perma-cool. you can connect it directly to the battery--and incorporate a relay to have turn off when you switch to ignition off.

[NISMO_RB25]

does it come with a probe or sender? I have been looking at getting a fan controller, but I really wan't something that I can just tie into the existing sender unit.

My concern with the aftermarket units I have seen is that they usually have a probe that you have to insert into the radiator hose, it is hard to get it to seal well, or at least I couldn't get it to seal well.

[nukeone]

For less than $25 at PepBoys, you can get a Hayden Thermostatic Fan Control switch that cuts on the fan(s) at 185 degrees F shuts them off at 165 degrees F. Also includes a wire for A/C relay connection so as to cut the fan(s) on/off with A/C activation. This is a complete kit; includes all necessary wiring, fused hot, wiring for 2 fans, thermo probe, relay... everything you need. If you want adjustable temp control, they also sell a similar Hayden kit for about $45. Good, easy to follow instructions, and easy to install.

[Bronze MFP]

Fan controler here. Comes on when needed and shuts off when not needed.

ditto,

FAL fan controller for teh win

[BoostFab]

yes, it has a temperature probe. and it's variable (adjustable). and yes, you can get other brand for cheaper. they're all the same s#$! =D ...they will seal fine if installed properly.

[s13_rb25det]

For less than $25 at PepBoys, you can get a Hayden Thermostatic Fan Control switch that cuts on the fan(s) at 185 degrees F shuts them off at 165 degrees F. Also includes a wire for A/C relay connection so as to cut the fan(s) on/off with A/C activation. This is a complete kit; includes all necessary wiring, fused hot, wiring for 2 fans, thermo probe, relay... everything you need. If you want adjustable temp control, they also sell a similar Hayden kit for about $45. Good, easy to follow instructions, and easy to install.

hmm... sound like the thing i am looking for... do u maybe have a link where i can purchase it?

and where did u connect the probe to?

thx @everybody for the help...

[nukeone]

Sorry, but I could not find a link. PepBoys carries them in stock for less than $25. The probe physically fits inside the radiator fins and comes with attaching pads/connectors. Very easy install.

[NISMO_RB25]

so the probe is actually external? That sounds like what I have been looking for.

[nukeone]

Yes, so you could physically put it almost anywhere. The instructions recommend putting it between the fins for most accurate temp indication at the radiator.

[NISMO_RB25]

Thank you. I will go hunt one of these down.

[johnzm]

what size/how many fans are you guys running?i got a single 14 and i swear its not keeping me cool mines on a fan switch comes on about 190

BTW i have AC so mounting on the front is no good, and im running a skyline radiator.

[Bronze MFP]

i'm running 2 12" pushers, so far my temps havn't gone above 90 degrees celcius when i'm sitting still