Hi everyone
I have a problem with my 954 fan not coming on when bike reaches silly high temps.. I have installed a seperately wired inline coolant hose sensor with a manual override to overcome this but would like to fix the factory system . I know the fan and relay work and temp reading shown on the display. ECM gives an earth when bike hits 101c so relay switches but no power 12v to fan. The strange thing is relay has 12v to the relay on the switched fan side when ignition is off but turn it on and no power.


​​​​Well after lots of testing I came up with jumping from the fan fuse g/r wire to g/f wire at fan relay with engine cold then jumping earth wire at the relay to the frame. The fan came on. I thought it must be bad wire to between it and relay. I tested the wire and no continuity with ignition on but it had continuity with ignition off as showing 12v. That is when I decided to jump the r/g wire and run the bike up to temp and now the fan works as it should turning on and off at the right temp. I haven't figured out the r/g wire problem as I would think it should be live when the ignition is on and not the other way around. Has anyone got any ideas on this? The ECM is giving an earth for the relay to switch when bike reaches 101c and the coolant sensor is good but power from the fuse somewhere down the line 12v is getting turned off along the g/r wire when the ignition is on. All seems good but just want to make sure this fix won't cause any problems before I permanently wire it in with a 20amp inline fuse. Maybe this easy fix might sort out the problems 954 owners have had with the fan not operating when they have carried out the normal checks of fan sensor and relay. Honda just making a simple system far to complicated.

I have jumped from fan fuse green and red wire to g/r on fan relay and all is good. Fan starts at 101 degrees C and stops at 97 degrees C.