[NMKawierider]

Because it looks like these older fan switches failing is more when then if, and my luck it will fail when I am out in the hot desert in an area I can't open it up to ram some air through the radiator, I decided to run a by pass just in case. So, first I ordered this switch to clip into the dash:

http://www.amazon.com/Laser-Backlit-Rocker-Switch-COOLING/dp/B00NQCZTG4?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

While I am waiting for it to come in, I traced the two wires from the switch to a point where I could open the harness and make the connections. There is a black/red and a green. The black/red is the 12V line:



Using 14g wire, only because that's all I had and 18-22 would be fine, I use two quick splice connectors. RED to the Black/Red and BLACK to the green:



It's about 32"s from there to the switch so I cut the two, wrapped then in tape and slipped them through some automotive shielding.





Routed it through the firewall and out the open switch hole and put a couple of wire ties on it.





I'll install the switch when it gets here. RED to line and Black to load.

I also like to seal things back up so after testing to make sure it works (just turn the key on and touch the two wires together), I coated the splices all the way around with liquid tape to make it water proof.





Then put it all back together. Piece of cake. Note that this will bypass the thermo or fan switch only. If the relay goes bad..this won't help but at least you will know where the problem is.

UPDATE: 4/9/16:

Switch came and installed. You will have to run a ground for the switches internal lights HOWEVER because the power wire to the thermoswitch is from the negative side of the relay on its way to ground through the thermoswitch, DO NOT use it for a power supply for the LEDs of the switch. Jumper from another switch's dash lights for power for the lower light and provide a ground for that light only. And because the upper LED is powered by the "LINE" wire, which is from the relay, you will not have an upper LED and do not provide a ground for it. Putting any load on this line will provide a partial ground for the relay and may cause damage to the relay coil or contacts or fan motor by being partly actuated.

[Derfer22]

Good idea..

[gfmoto]

👍🏻👍🏻👍🏻
Waiting on mine to get back from the shop. I'm going to do the same , however AFTER the warranty is up.
Nice work by the way!

[Revolutionary]

NMK, I just got my new thermo sensors in, I know they go on the radiator somewhere (I think) so where at, please? I want to install a bypass switch on them too, but that comes when I have more time....right now, I'd like to replace the thermo sensors, (is that the right name?) as I know they're prone to failure.

Help appreciated-
Chris

[NMKawierider]

NMK, I just got my new thermo sensors in, I know they go on the radiator somewhere (I think) so where at, please? I want to install a bypass switch on them too, but that comes when I have more time....right now, I'd like to replace the thermo sensors, (is that the right name?) as I know they're prone to failure.

Help appreciated-
Chris

Look through the wheel well on the passenger side toward the radiator. As I recall its about 3" below the hose on that side...the only thing that has wires going to it. Have your new one Teflon-taped and ready to go as I believe it's threaded right into the coolant...release any pressure from the cap before taking it out. Might take the wheel off to make it easier to get to.

[Revolutionary]

Thanks very kindly, NMK. Excellent info, I'll do it maybe this weekend....

[ACIDICJO]

Love this forum, had to rig a jumper while out in the woods and now I'm gonna do this. Thanks NMK.

[NMKawierider]

Love this forum, had to rig a jumper while out in the woods and now I'm gonna do this. Thanks NMK.

Funny thing is for me... my thermo switch is fine so I never had to use it. But in the wise words of my late father -" It's always better to have and not need then to need... and not have"

[glenlivet]

Great write-up. I'm going to do this, already did on my King Quad just in case of a similar failure, which never happened. (Have a heavy duty night switch in line with the battery negative too so that in the event of a wire short I can cut the battery out immediately. Never had to use that either, but I did help a Can Am rider hurridly get at and disconnect his battery when his ignition switch shorted out. Seemed to take forever.)

I'll need a different switch location though, as the one you used is occupied with my hazard light switch and the one above is my turn signals.

Thanks for coding the wires, saves lots of time.  Another cool thing you can do is hook up a 12 volt indicator lamp parallel with this switch. The light will be on when the switch closes (fan runs) and off when it stops. Then you know when your fan is running when noise blocks out any sound. Interesting thing, when the fan switch opens the fan whirls to a stop and the light will gradually glimmer its way off! That's because for that second or two the fan is acting as a generator, as long as its momentum keeps it turning.

[NMKawierider]

Another cool thing you can do is hook up a 12 volt indicator lamp parallel with this switch. The light will be on when the switch closes (fan runs) and off when it stops.

Actually with this CFM system you don't want to do that off this sensor lead. I already tried it and had a problem. It was then I decided to look at the wiring diagram...lol.  That Black/Red lead although it had 12 volts on it, it is passing through the relay coil on it's way to be grounded through the thermoswitch...(the green goes straight to ground) to activate the relay coil. Any additional load on that line pulls that load through the relay coil which offers a high resistance which causes the voltage to drop so far the light won't get enough to light..even the LED in the switch..which was my case.. or the resistance through the LED may not allow the relay coil to gain adequate ground to energize the coil. So...If you feel the need to have an indicator light on it, tap the 12 volt lead to the fan itself which is on the load side of the relay. 

[Arizona Bushman]

Just a modification on the idea. It was going to be too difficult to splice in where you did, at least for me. I got at the black/red stripe wire where the harness traverses under the storage. The other wire I spliced onto the horn ground wire. Works great. Thanks for the idea. It gets hot in the foothills north of Phoenix and don't like the idea of pushing it back.

[Arizona Bushman]

Because it looks like these older fan switches failing is more when then if, and my luck it will fail when I am out in the hot desert in an area I can't open it up to ram some air through the radiator, I decided to run a by pass just in case. So, first I ordered this switch to clip into the dash:

http://www.amazon.com/Laser-Backlit-Rocker-Switch-COOLING/dp/B00NQCZTG4?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

While I am waiting for it to come in, I traced the two wires from the switch to a point where I could open the harness and make the connections. There is a black/red and a green. The black/red is the 12V line:



Using 14g wire, only because that's all I had and 18-22 would be fine, I use two quick splice connectors. RED to the Black/Red and BLACK to the green:



It's about 32"s from there to the switch so I cut the two, wrapped then in tape and slipped them through some automotive shielding.





Routed it through the firewall and out the open switch hole and put a couple of wire ties on it.





I'll install the switch when it gets here. RED to line and Black to load.

I also like to seal things back up so after testing to make sure it works (just turn the key on and touch the two wires together), I coated the splices all the way around with liquid tape to make it water proof.





Then put it all back together. Piece of cake. Note that this will bypass the thermo or fan switch only. If the relay goes bad..this won't help but at least you will know where the problem is.

UPDATE: 4/9/16:

Switch came and installed. You will have to run a ground for the switches internal lights HOWEVER because the power wire to the thermoswitch is from the negative side of the relay on its way to ground through the thermoswitch, DO NOT use it for a power supply for the LEDs of the switch. Jumper from another switch's dash lights for power for the lower light and provide a ground for that light only. And because the upper LED is powered by the "LINE" wire, which is from the relay, you will not have an upper LED and do not provide a ground for it. Putting any load on this line will provide a partial ground for the relay and may cause damage to the relay coil or contacts or fan motor by being partly actuated.

The only difference in my installation is I used the ground side of the right horn and soldered all together. I felt it more durable and reliable.

[REDRIDER]

In case you run into a thermos switch failure on the trail and don't have the bypass switch set up. Emergency fix (because it happened to me). I didn't have a paperclip which would have been nice, or a jumper wire. I cut a small length off of the steel braid on the brake line, removed the thermo switch connector and jumped the terminals on the connector with that. Worked for an hour to get me home.

[dragonmac]

had to do it myself as an emergency two weeks ago...used the aluminum pull tab from a beer can, split it in the middle and jumped the terminals and taped with black tape....will be adding the extra switch for future rides....thanks

[Jaco499103]

Just got the switch (same as shown). I need the wiring diagram.
Thanks.