Radiator fan


  • Does anyone know where the relay is for the fan on a 99 shadow 750? my fans are not kicking on but the temp light came on so I know their is an issue, I just picked up my first bike and noticed it was pretty low on coolant so i decided to do a flush and fill on the coolant system as I was burping the coolant about 15-20 went by of ideling and the temp light came on I shut it off and check the fuses and couldn't find the relay, I also disconnected the thermo switch and grounded it turned the key on and the fan did not kick on so I'm assuming the fan is the issue but if the issue is a relay the fan probably wouldn't work either way so I'd like to check that out first before buying a 5 inch fan and wiring it to a switch that I can control myself, thank you for any info guys! 



  • @mattylz your temp sensor could be bad, or stuck. Have you rebuilt your thermostat? That bike should not overheat in 15minutes of idling unless youre sittin on the surface of the sun.

    You just stated that when you grounded the fan switch the fan didnt come on. the switch is bad. with the key on, the fan switch should turn the fan on if you ground it. you can test the fan by punpluggin it and then connecting each lead to diff poles on a battery. if the fan turns on connected to a battery, then the fan is fine.
    whats more concerning is that the engine overheats, you can burp and flush all you want but if the thermostat is toast then you wont get anywhere. replace the thermostat, then go from there. its 25 years old. its time. 


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