temp light

Hi All
Quick quiz question 
Had a 60 mile ride today round Gtr Manchester and Cheshire. "A" roads not motorway.
Temp light came on half mile from home.
Fan was switching on and off as required and the bike seemed ok.
Took her home and checked the coolant level which is up to the neck and looks fairly new.
No fluid loss or leaks.
Left her to cool for a couple of hours and went out to put her away.She was fully cooled.
Temp light came on and stayed on for the few minutes I ran her whilst putting her to bed.
Not had any signs before and not sure where to start.
Thanks in advance
Spudz
Mark

Hi Mark, I have had a similar problems to this fault,  several years ago on my uncles VZ800 Marauder, if my memory is working right I believe the temperature sensor and the oil pressure sensor share the same earth, and the neutral warning light/ oil warning light/ and tem warning light share a common feed  (It`s a weird system) anyhow the fault was a corroded wire on the oil switch ( the switch is always getting covered in crap because of its position) the wire was repaired and a new oil switch fitted and the temp light stopped coming on intermittently, a weird fix I know but it worked, I shall try to find the book I kept servicing records ETC in and see if I can find some better info for you but in the mean time it may be worth checking the wires for corrosion ETC.
You mentioned in a previous post that your bike does not like siting in traffic as the fan cuts in and I recall saying my VZ idles for ages before the fan comes on,,, this leads me to a fan/ temp warning light coming on on a friends VZ800,,, it was getting too hot because of the chrome radiator cover was far to restrictive to cooling air flow even with the fan on it struggled to cool the bike,,, removal of the radiator cover cured the fan/temp light problem immediately,,,, I know you said you let the bike cool down and the light stayed on but mate if you have a radiator cover it may be prudent to remove it and see if that helps,,,,A faulty/broken water pump will cause both of these faults, I think I have some info on that and as I said earlier I shall check my book and come back to you,,, my VZ800 doesn't run a chrome cover, my M800 does but I don't have a problem at all with it. The VZ800 is a weird but also wonderful bike.
Hope this is of some help Mark.

Hi john
Thanks for this I,ll check it out asap. I don't have a chrome cover on as yet and may now not bother.
It seemed a bit weird how it happened. It was still on some 3 hours after the bike was shut down.
Any further help would be appreciated
Thanks Again
Spudz
Mark

Hello Mark,
Sorry for the delay,,, cannot put my hands on relevant papers,,, if still on after 3 hours I would very strongly suspect a faulty/broken/chaffed wire,,, even though I solved my problem I still replaced the sensors,
I had a broken wire/connecter for the neutral light, wasn't on when the bike had been standing for a while after about 10 mins riding it when bike was hot neutral light came on all the time but the bike would have to stand some 6 to 8 hours before it was cool enough for the connection to re-make,,, broken wires connectors can cause those symptoms
Keep us informed mate, we like to know how your getting on,,, see if we can get it fixed.