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Discussion Starter #1 (Edited)
My radiator fan is dead so I ordered a used one that was removed and supposedly in working order. I am trying to test it using a battery before I put it on the bike and can not seem to get it to work. I would like to confirm it is working properly before installing it on the bike. I had thought it should be as simple as connecting the ground wire from the connector to negative on a known good battery and jumping the third wire to the positive. The fan actually has three wires coming off of it, two running to a connector and a third wire that is separate (+)? Am I correct in assuming the fan should come on when connecting the third wire to the positive side of a known good battery and the ground from the connector to the negative side of the battery? Tried that and fan does not come on so wondering if the fan motor is bad?
 

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Discussion Starter #2 (Edited)
Looks like I just answered my own question in case anyone else wants to do this with the fan off the bike. The black connector needs a jumper wire connecting the two leads. The ground cable directly to the battery ground. The third wire which I am assuming is the thermostat wire directly to positive. Fan now runs and motor checks out good. Was afraid I paid $100 for a bad fan. Hard to believe that a new fan motor (if you can find it) is $250.
 

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Discussion Starter #4 (Edited)
Yes good point. I was trying to get one quick and found one on Ebay so decided to "jump on it" while I had the time to deal with it. Felt fortunate it worked as it should because with used parts on Ebay sometimes you are taking a chance. Was afraid also being an
SP1 might have been more challenging as it seems more SP2 stuff out there these days and the SP1 fan is different.

I am planning to do the manual switch mod at the same time but am not that mechanically/electrically inclined so this is probably a stupid question. I have looked at the post showing the wiring diagram and am apparently missing something that I don't fully understand? It would appear that by splicing the positive wire of the switch into the temperature sensor wire that the switch would not make the fan come on unless the temperature sensor is already above the "tripping point"? It was a post by "Jondog9" back in 2016 but was unsuccessful copying the diagram here. Also curious if others think this is really worth doing given it seems that the fan does not do much good while the bike is moving anyway and turning it on will put more wear and tear on the fan motor?
 

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The temp switch switches the negative. If you want a manual fan switch you connect the temp switch to ground.

Or I'll build you one for 40 bucks. Plug and play
 

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Discussion Starter #9 (Edited)
https://www.rc51forums.com/forums/60-how-articles/73154-sp1-fan-toggle-switch.html

Ok. Thanks guys. This is the wiring diagram I was referring to. Hope the link I posted above works. Is this what you mean by wiring "parallel to the sensor" or am I still confused? If I am going to install a manual fan switch I was still wanting the temperature sensor to turn the fan on even if the switch is in the off position if that is possible? Sorry for being electrically illiterate. Apparently in that post there was a guy who tried to do this and it did not seem to work correctly so just making sure the information in that original post was accurate.
 

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Discussion Starter #11
Ok guys, once again I think I answered my own question. Looking at the diagram, the ground from the temperature sensor should not be interrupted by the switch with the wiring setup as suggested in that post. It makes more sense now but took me a bit to understand. Still not sure how beneficial it will be to activate it manually early but it was a puzzle trying to figure it out and as you can see a learning experience.
Not sure exactly where to mount the switch and if it is really necessary but may serve some purpose to turn the fan on a little early I suppose. I will just be happy to get the fan working again!
 

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Discussion Starter #12
Fan and switch are now working and made a huge difference in the operating temperature of the bike (no surprise). It never really was a problem because I rarely rode in stop and go conditions. At least now I have the option to do that without having to turn off the bike at traffic lights etc. I was hesitant on doing the switch mod but definitely recommend and glad that I did. I can anticipate the stops and keep the bike cooler by turning it on around 200 degrees rather than waiting to 217.
 
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