Hello all....just popped into the garage to get something; heard a fan running. My 2005 999s under its cover, blankets, optimate plugged in, key out of the ignition - the RHS fan is running away on its own. WTF !? Battery is run right down. Put ignition key in and not enough to run start up on the dash. I've just had time to whip out the battery and plug it into the optimate. Will investigate later after work.... ....but any clues as to where to go for this one? thanks Paul
I have never worked on a 999 From past posts on hear headlight and fan relays are poor I would change the relays first and see if that cures it Nothing like the same but I had a 910 Brutale. They have a central control unit for the electrics and early ones were terrible for just failing. I went in the garage and found the lights on didn't stop the bike working but needed a new CPU at £200 Some vehicles when hot have the fans running even when the key is out and don't stop till the signal from the temp sensor drops. Don't know if 999 are like that but if so it would point me to the relay
There are no relays fans are run direct from ecu. I had a fan issue that meant one fan ran constantly but only when ignition was on. I would think you have some chafed wires, that is a constant live touching a fan wire. Just follow the fan wire back to the ecu checking for damage as you go. This might involve getting into the dreaded battery box which is a bit of a bastard Good luck
Look at major connectors and the fuse box, maybe a short in the back. Is the Ignition relay close to fan cables?
If you can download the handbook/manual as a pdf then you can zoom in on the wiring diagram. Its a huge help.
thanks all I've got the manual - I bloody hate electrics. No problem doing belts, have rebuilt gearboxes blah blah. But dead things going click and nuthin' just tick me off. Odd that it has gone just in a cold snap......weird hearing it whirring away on its own. Spooky !! I will do as suggested and trace all the wires back. Hopefully it hasn't written off the battery. Go through too many of those. Will wait til the weather warms up though - unheated garage. Told my missus the bike should be in the conservatory (@Exige) One last thought - what is it that 'tells' the fan to run after ignition off on a hot day? Presumably a thermostat somewhere? Could that give a false positive reading back to the ECU? Where is it located on the bike? thanks all
Both fans are connected directly to the battery via the 40A main fuse. There is no relay and they are turned by the ECU providing an earth when the coolant temperature reaches a certain level, usually around 105ºC and turns them off when the temperature drops back down to around 98ºC. The ECU gets the temperature reading from the coolant temperature sensor which it also uses to adjust the fueling, richer at cold temperatures and leaner at higher temperatures. The only way the fans will go on by themselves is either there is a short to ground in the wires between the fan and the ECU or the ECU itself is faulty and is providing the path to ground.
Ultimately that's the goal Exige - saw your piece in Performance Bikes was it? - no to hanging it on the wall, but on a plinth is a defo' possibility
Brilliant sir - many thanks. Let's hope a bit of insulation tape and not a new ECU. Given it was one fan, suggests the former. Ta
Except that the fans are not turned on simultaneously. Iirc, they come on sequentially, the first at 101, then 103 degrees for the second one if the temperature continues to rise Fingers crossed it’s a wire though
Sometimes its really hard to love my 999. Went for a 150 mile ride out on sunday, while held up by the east coast mainline I thought I,ll let the engine temp rise and see if the fans cut in. At 105 the left fan came on and temp reduces all good I think. I get home and turn off but the fan keeps going, several on and offs of the ignition and fan stops. Put it in the garage and watch wsk, have nap and get ready for pub. Go back to the garage and the fan is running. Only thing to stop it is to disconnect the battery. While doing this the right angled connector on the loom lead comes away in my hand, just falls off. Seems it had fractured and was hanging together by a thread. So I fabricate (bodge) a repair, (there is very little wiggle room in there), and all seems well. I really need to run it through a heat cycle or two before pronouncing it fixed but Im hopeful. Since this lead goes to the relay it would tie in with what @chrisw says. Hope this might help anyone in the future.
Sorry I wasn't very clear on that. I have Mr Exiges finest fitted, it was the oem terminal connector that broke.
made me smile with thoughts of an off-topic similar:- parked my little Fiat 500 in centre of Woking. there were all sorts of industrial noises coming from buildings there but I still thought something was wrong. Opened 'boot' of car to find dynamo was happily spinning away - I'd thrown the belt just as i had switched off engine and dynamo had turned into a motor!
