How to Install a Fan Switch...

[Eclipze]

How to Install a Fan Switch...

A fan switch is a good backup in case the thermo switch fails. They don't have a good reputation for reliability, and when it fails, you'll only find out when your engine has become too hot, on a nice hot day, and only when your at the furthest point from where your house is

The other reason... is if your a lazy cheap fart that can't be bothered to replace it . The OEM ones are really expensive too, but there are cheap alternatives. Check k916's maintenance thread on the radiator/cooling.

To get the fan on, all that is needed is to ground the control wire for the fan relay. Thats all the thermo switch does.

The thermo switch is located in the bottom left of the radiator. Pull the terminal off the thermo switch, and reconnect it with a male to female pass through... and tap off this for the switch. (or you could just hack into the thermo switch wire )

Route this wire up to a switch, and then from the switch to a ground point. The ground point can either be in the wiring harness or connected to a convenient point on the chassis. I've choose to mount the switch on the fake ram air duct, and connect the ground to the fairing bolt hole with a wire soldered to a washer. The washer just gets sandwiched on when the fairings are bolted on.

To make things neat, I drilled two small holes in the fan shroud and cable tied the wired in place.

The switch really needs to be mounted on the left hand side of the bike, so it can be turned on/off while riding, without slowing down

I'd recommend either a water proof switch, or a water proof rubber cap screwed on. With ignition on, the fan will now turn on when either the fan switch is on, or the thermo switch turns it on [nod].

Below is a picture of the fan switch. Note, I placed a bullet type connection in there for when I need to remove the duct. You could just unplug it from the bottom, but the bullet connector will pop out in case you forget , and avoids needing to cut the cable ties.

[Big Al]

Great mod!
Along with removing the limiter it's one of the best things you can do for your ciblet.

[Shiftd]

i've just installed this.... probably one of the easiest mods ever...

*where was this in summer!?@!*

Thanks again Tony!

[mat_p]

just bumping this up as im about to do this as my poor cibby gets a touch warm...probably a good time to bump it considering summer is coming up quite quickly now.

[Aduro]

^ checked your coolant and oil levels first?

[sir.b]

Fan switch was one of the best mods I did on mine. Having manual control over the fan allows you to turn it on as soon as the bike warms up on hot days, which makes a big difference when you find yourself in heavy traffic and not getting enough airflow (or god forbid, stationary for a long time). I did this mod because my thermo switch was knackered, but I'd do it even if it worked.

On a similar note, my 600RR's fan kicks in at 104 degrees, and I'd love to make it kick in a little earlier. Any ideas guys *cough* Tony *cough* ?

Justin.

[Eclipze]

CBR600RR 06/07... I reckon it would be pretty straight forward. The fan is controlled by the fan relay. The ECU controls the relay via the orange/blue wire going to the relay. The ECU probably just uses an open collector driver to drive the relay, and expect you could just drive it in parallel with a switch. i.e. switch to ground should do it. It would be good to take some measurements with the multimeter just to be sure before doing it, but reasonably confident it would work a treat. The hardest part is going to be what type of switch to use and where it will fit. I'm thinking a rocket launcher style flip cap switch

[viper33]

well my fan turns on by itself but my bike still used to run hot
found out it was the thermostat that needed replacing
so before you go doing the mod, check if the fan switches on or not
coz it could be something else

[sir.b]

(26/10/2010 10:14)Eclipze Wrote:  The ECU controls the relay via the orange/blue wire going to the relay. The ECU probably just uses an open collector driver to drive the relay, and expect you could just drive it in parallel with a switch. i.e. switch to ground should do it. It would be good to take some measurements with the multimeter just to be sure before doing it, but reasonably confident it would work a treat.

After you mentioned this I did a quick search on 600rr.net for a fan switch mod and found this:

1.Remove the 3 bolts on the Left side ( the clutch lever side ) mid fairing and any other push clips holding the fairing & Remove.

2.There will be 3 Relays next to each other with wires coming off. Seperate the MIDDLE relay.

3.There are 4 Wires coming out of it as follows:

-Black/White = Ground
-Blue/Black = Fan
-Blue/Orange = Constant Power (12v)
-Blue/Green = Trigger (what triggers the relay, works when 12v is applied)

4.Strip a section on the Blue/Black & Blue/Orange Wires.

5.Soder a seperate wire to each wire: ( Blue/Black & Blue/Orange ).

6.Connect the ends of the wires ( the ones you just added ) to the switch.

7.Tape everything up ( or heatshrink )

8. Now the switch can activate the fan at any given time, but remember to turn it off.

I can't find my 600RR schematic Guide above suggests that orange/blue is power and it switches by applying 12V to blue/green. Confuzzled :/

Justin.

[Eclipze]

Ok... first off, I've found a better quality wiring diagram. The low quality letters I thought said O/Bu, but on the good hi-res one it's definitely G/Bu (Green/Blue). My bad :-)


Black/White
Is not ground. It looks to me like the Black/White is an ignition power feed from the ECU. Beside that, Honda have used a green based wire colour for all ground.

Black/Blue
It's black/blue, not blue/black that provides power to the fan. By the way, the other wire on the fan is a green one, connected to ground :-P

Blue/Orange
Constant power... always has power from battery.

Green/Blue
Not blue/green... darn newbs. The ECU uses this to trigger the fan.


The guide from 600rr.net puts a switch in parallel with the relay. If you have a switch between shorting these two pins, your fan will come on... even if the ignition is keyed off. You'll need a high current switch and good gauge wire to carry the current.

The alternative I mentioned will only allow the fan to be activated when the ignition is on. You'll only need a low current switch and thin wire too, as it's just driving the relay. Aka... a wire from the Green/Blue to the switch, then the switch to ground somewhere (i.e. Frame bolt or a ground wire near where you want the switch).

That help?