help! ktm fan kit

i am not familiar with the kit by any means but am familiar with wiring, if your fan runs with the thermoswitch unplugged then its getting power and ground from somewhere directly to fan without going through switch, recheck your wiring, if this kit is a plug and play kit i have seen other premade kits (trailer light kits, car accessory kits etc , not your fan kit) come with wires backward in the harness, id start by checking power and ground at wherever the fan harness attaches to your stock harness... a lot of diffenet scenarios could happen if one wire gets switched...
when i installed my homeade fan kit i was going to take power from headlight circuit, acidently tapped into the wrong red wire and when i actuated the fan switch the starter also tried cranking and the fans turned on at same time, i resspliced to the other red wire that was actaully for the headlight and not the e-start button and was good to go lol, didnt take long to find that mistake, glad it was in neutral 8O
good luck

The thermo switch has the ground from the fan coming to it, and then when closed completes the circuit to ground. So if the fan is running when the two wires at the thermo switch are disconnected then the leg from the fan motor is getting a ground some how and completing the circuit.

If the two leads to the thermo switch are touching the fan will run.

Is the fan running with the motor off?

Thermo Switch Part Number 78035045000
The Thermo Switch contacts are Normally Open (NO).



Fan Wiring diagram below, should help you:

If you've disconnected the two wires from the thermo switch ... and they're not touching each other ... and your fan *still* runs ... then you have a possible plug-in issue or a short in the fan wiring itself.

Cheers, E-Ticket

erniebearskin said:

Ahhhh, good times. So yesterday afternoon, I am doing a load of my 3 year old sons laundry and what do I find? Part 2 of the wiring harness (section containing fuse holder). Wiring the fan makes alot more sense now. Unfortunatly I may have damaged the one white plug end on the Husaberg harness as the fan now will not start, last night I let my bike idle to near steaming point and no fan kicking in. I believe this project may be doomed.

Click to expand...

I'm very sorry ... but I can't help myself! BWU-H-hAHAHAHAh ......!!!
Oh geez, just when you think you have heard all the possibilities for things going wrong.

BTW, you can test the fan without having to melt your engine. Pull the rubber boot back (old-style connector) on the thermo switch, or slightly disconnect the spade connectors (new style connetors) on the thermo switch ... and use a small screwdriver to short between the two spade connectors on the thermo switch. That is, you're shorting the two spade connectors together.

This will mimic your thermo switch getting hot enough and "closing" the fan power/ground circuit. And then your fan should switch on. Remove the short ... fan should switch off. This should make it easier to test when you find out what's going on.

Best of luck, sir! E-Ticket

Does anyone know what would make the thermoswitch crack at the white plastic around the electrical connections? My 2011 Fe-570 S only has 23 hours on it and I put the fan kit on right after I bought it October. It has worked flawlessly as far as I know until now. Now, the fan stays on all the time and after a process of elimination, I finally figured out the thermoswitch was letting the fan run constantly. Upon inspection, it is cracked and I can't figure out what would make that happen other than heat??

Electrified said:

Does anyone know what would make the thermoswitch crack at the white plastic around the electrical connections? My 2011 Fe-570 S only has 23 hours on it and I put the fan kit on right after I bought it October. It has worked flawlessly as far as I know until now. Now, the fan stays on all the time and after a process of elimination, I finally figured out the thermoswitch was letting the fan run constantly. Upon inspection, it is cracked and I can't figure out what would make that happen other than heat??

Click to expand...

Perhaps the thermoswitch was over torqued. For a replacement, use the much less expensive 'accessory fan switch' for an '04 BMW 318i available at your local auto parts store. I suggest a 95/90 C unit.

Chas said:

Electrified said:

Does anyone know what would make the thermoswitch crack at the white plastic around the electrical connections? My 2011 Fe-570 S only has 23 hours on it and I put the fan kit on right after I bought it October. It has worked flawlessly as far as I know until now. Now, the fan stays on all the time and after a process of elimination, I finally figured out the thermoswitch was letting the fan run constantly. Upon inspection, it is cracked and I can't figure out what would make that happen other than heat??

Click to expand...

Perhaps the thermoswitch was over torqued. For a replacement, use the much less expensive 'accessory fan switch' for an '04 BMW 318i available at your local auto parts store. I suggest a 95/90 C unit.

Click to expand...

Thanks Chas. Went down and picked one up at the auto parts store for $24! KTM wanted $52. Much appreciated. :mrgreen: