fan not cutting in after i have changed coolant

[blackie1]

K1100LT
recently i completely drained and then refilled coolant
i had garnered as much info off here prior to doing so
when i had refilled coolant i idled the bike with the radiator cap off and squeezed the bottom hose (as much as i could as it was a bit tight with the fairing obstructing me) to try and release any air bubbles.
i couldn't squeeze the hose and view the open radiator at the same time so i don't know if any air bubbles were expelled or not.


during the next couple of weeks i rode the bike twice. each about 100km rides . all good temp gauge sitting in normal range. it is winter here so no real chance of overheating.




last week i left bike idling on center stand on purpose to see if the fan would kick in when things got too hot. in the past it the fan has operated perfectly.
this time I watched as the temp gauge passed normal then moved on past where the fan would normally kick in and continued to climb and  coolant started to get pushed out of the overflow


it became obvious that the fan wasn't going to kick in so i shut her down.


i realize that the coolant change and my fan stopping working may be completely unrelated and just coincidental
but my question is could an air bubble in the system somehow stop my fan from kicking in. if the air bubble happened to be sitting exactly where the sensor is that triggers my fan i thought that could be a reason.


i have since read that elevating the front of the bike whilst trying to massage the bottom hose may help in expelling any bubbles.


tomorrow I plan to elevate front of bike , remove radiator cap, idle the bike back up to temp whilst squeezing the bottom hose again.


then i will reassemble and do the same as before allowing my bike to idle up and over normal temp to see if fan will kick in.
if it fails to kick in i guess i will start testing the fan itself as described on other posts.


any advice or pointers appreciated

[Martin]

First check fuses.OEM fans had a tendency to cease working, seize and melt brushes. Is it the original OEM fan? Can you get you hand finger stick or any other thin object and see if the fan blade rotates easily. If it is seized the best direction is to replace it with an after market Spal fan. I replaced mine 18 years ago with a Davies Craig fully sealed fan and have no problems since. If you do have to replace your fan it is also a good move to fit an over ride switch, it will give you peace of mind.
Regards Martin.

[blackie1]

hi martin, thx for the speedy reply.
fan does move but it does some a little stiff, don't know if i would say it moves freely. yes it is OEM fan.
i have just run it back up and over temp and it still is not cutting in so i guess your advice to troubleshoot electrics is next on the cards. i will begin with the fuse then move on to  by passing or jumping  the relay as described elsewhere  . thx

[Martin]

Blackie should not be stiff, it should rotate easily. If you do manage to get it going it would benefit from a clean and a lube job.
Regards Martin

[blackie1]

ok cheers for that

[bizzaro]

Blackie,
Have you tried the fan test?  You can make your fan run by (this is how I do it)  Key off.  On the center stand. Side stand up. Bike in neutral. Now ground pin one of the "diagnostic plug" under your seat.  Turn on the key and hold the ground for like 5 or 6 flashes of the console(abs) lights. Now disconnect the ground.  The fan should pulse on and off.  That will tell you if your fan is "good".  I have also found my fan to be a bit fickle when it comes to turning on and off.  It doesn't seem to have a consistent starting point, but rather depends  how long it has been in the hot range.  When I first got the bike it wouldn't come on till it was way in the red.  The other day it was running at 3/4 plus on the gauge for maybe twenty minutes and I was pleasantly surprise to hear the fan fire up well before the red!  Probably an inconsistent sensor, but hey, works for me!
Bizz

[blackie1]

thanks Bizz
I have found the blue "fault code reader" socket under the seat . will try out your advice this weekend, cheers big ears lol

[bizzaro]

Good luck with it.