adding a rocker switch to control radiator fan

[wheeliedad]

Trying to put a rocker switch on my 04 450r to be able to control the fan running when i am drag racing. I have 2 wires-1 green and 1 blue, coming out of the fan and goes up to a connecter and 2 wires come out of it-1 green and 1 blue. not sure where these go from here but when the bike is running, they are both hot. I have one wire coming out of the sending unit that is on the engine that is yellow with blue stripes. To install a rocker switch to be able to have the fan running not only when the thermostat kicks it on but also when i turn the rocker switch on, do i run one wire from the rocker switch to the yellow with blue stripes wire and one to the green wire? And do i need a ground wire from the switch too? if not, how do i wire it? Thanks for your help.

[JBENSON]

There is 1 wire that goes to a sensor on the cylinder head, unhook the wire from the sensor and ground it to the frame somewhere. Your fan will the run whenever the engine is running.

[DnB_racing]

just to make sure I understand what you want...your trying to have the t-stat sending unit be normal but with a bypass switch to run fan anytime you want even if its not up to temp??


if so you will have to have 2 separate feed wires one from t-stat and one from bypass,

if this is what your looking for you would take the hot from the regulator and bring it to the fan with a toggle switch in series with it and a separate ground, then you would have to put a diode in line with the existing wire from cdi so you dont back feed the cdi every time you turn the fan on


or the easiest way is to just use the switch and get rid of t-stat sending unit, by putting the wire from sending unit to ground with the switch in series with it..

EDIT""""I over thought that lol...yes you can just run another wire with your switch to ground with the sending unit still hooked up same feed so no isolation would be needed

[DnB_racing]

just add something like this and it will work the way you want,

***just know evertime you turn on the fan with the bypass switch your temp light will come on****

[CJM]

Couldnt you just add a toggle between grounding out the wire?

[DnB_racing]

LOL!!!yes just before you posted I edited my previous reply. the pic above shows just what you just said

[CJM]

haha great minds think alike lol.

just to clarify, that wire appears to be yellow with a black stripe?

[wheeliedad]

Wow. Thanks for all of the information. i will start on this tomorrow afternoon. I have a relay already on the bike from where i had installed a horn so i believe i can use it. Thanks again!!!!

[DnB_racing]

Originally posted by CJM
haha great minds think alike lol.

just to clarify, that wire appears to be yellow with a black stripe? its should be yellow/blue
I will have to make that correction on the schematic

[wheeliedad]

Thanks again for all of your help!!!!

[wheeliedad]

This is great!!! THANKS

QUOTE]Originally posted by DnB_racing
just add something like this and it will work the way you want,

***just know evertime you turn on the fan with the bypass switch your temp light will come on**** [/QUOTE]

[Scro]

I could be reading this wrong, but with this setup, it seems like the only time the fan would run is when the switch is turned on? If the switch is off, how is the thermostat still controlling the fan?

[CJM]

Originally posted by Scro
I could be reading this wrong, but with this setup, it seems like the only time the fan would run is when the switch is turned on? If the switch is off, how is the thermostat still controlling the fan?

I think your right. Only way it would work both ways is perhaps if you had a 3 way switch rigged up for Off, On and stock.

I havent really looked into doing this much, but I suppose its possible you could rig it up so the switch is inline with the wire. But then grounds out to the frame. Flip the switch and it comes on just like if you grounded it to the frame, leave the switch off and it works as normal.

[wheeliedad]

Hooked it up with one of the wires from the switch to the ECT wire _yellow with blue strips_ and the other one to a ground. Instead of splicing the switch wire to the ECT wire, i used a trailer connector where you lay the main wire in it and the new wire in the other part and crimp the metal piece thru the plastic. This should let the fan work with the switch and automatically if you do not have the switch turned on, I BELIEVE. I know it did on my Polaris 500HO.
Thanks everybody again for all of your help!!!

[DnB_racing]

Originally posted by Scro
I could be reading this wrong, but with this setup, it seems like the only time the fan would run is when the switch is turned on? If the switch is off, how is the thermostat still controlling the fan? the thing he will have to do is parrellel the switching devices,(toggle,and sending unit) so if either goes to ground it will run

here is a rough drawing to help show what has to be done

[CJM]

So splitting the wire at the cdi to the switch and then a ground should work fine if I understand your diagram DnB?

[DnB_racing]

Originally posted by CJM
So splitting the wire at the cdi to the switch and then a ground should work fine if I understand your diagram DnB? yep just ground one side of toggle, and other side goes to the yellow/blue wire, and leave the sending unit untoched

[CJM]

Originally posted by DnB_racing
yep just ground one side of toggle, and other side goes to the yellow/blue wire, and leave the sending unit untoched

Thanks for the clarification.

I vote this be included into the sticky :)

[wheeliedad]

Put mine on yesterday and it works great. Put my sons (ghott) on today with an inline temperature gauge. With the switch off, the fan came on automatically around 210 degrees and when it got down to around 200, it went off. Then we turned on the fan with the switch and it cooled it down between 185 and 190. Everything worked great. Now we have the best of both worlds. Ran one wire from the ECT wire to the switch and the other wire from the switch to a ground. Will be great for ATV drag racing on sunday. Thanks again for all of your help