Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > Sport Touring: ST4 / ST3 / ST2 > my fan seems to have packed up

[mc31@york.ac.uk]

Usual culprit for this is the relay - under the seat. Easy to get at, easy to check and replacement is only a few quid even from a main dealer.

By the way - the fan comes on around 220 farenheit if that's what the readout is in.

[Glyn]

i had this problem, tried every thing never did get to the bottom of it.
checked the whole lot wiring, relay and sensors in the end i gave up and ran a new feed to the fan with a switch that i manually turn on and off.
i suspect in my case it was the ecu?

[bradders]

what Norman says...what I did with mine when it had the same problem to track down sensor, connection or relay issue

[skidlids]

As mentioned different STs have different systems, if its a ST3 with a 5.9M ECU it will be controlled by a Negative Temperature Coefecient (NTC) sensor that once its resistance reaches a given value the ECU turns on the fan,
For an ST2 with a 1.6M ECU the Fan is probably controlled by a themostatic switch.
Removing the 2-pin connector from the switch and shorting out the two connector pins with the ignition ON should make the fan come on, if it doesn't then either the fan is faulty or a relay or fuse has gone.

[YMFB]

My bike is an 04 ST4

How can identify the location of the relay and fuse that could be preventing the fan working.

[bradders]

you not got a wsm steve? try here http://www.carlsalter.com/motorcycle-manuals.asp

[YMFB]

Thanks Paul, but I have one, however, it doesnt say which fuse or relay protects/switches the fan.

It does tell you how to test relay. Although I dont have a multimeter tonight I can get one from work tomorrow so I put 12V across terminals 85 & 86 on the two relays mounted near the fusebox on the LHS of the headlight and they both click. So unless someone can point out something else it looks like its that damned fairing off again, grrrhh.

And that folks will be any chance of me getting out again this weekend unless I very lucky as its the kids sports night tomorrow and I will be working all day Saturday so that leaves Sunday.

Just recently vehicle maintenence time is exceeding use by about 2:1, not all the Ducatis fault as much time is also being spent on the VW camper.

[YMFB]

I have removed the LHS fairing, disconnected the fan at the big white connector and applied 12 v directly from the aux socket and the fan works, so it isnt that.

Where is the relay than switches the fan on/off located ?

Or should I be looking for a thermostat, if so whereabouts.

Either my eyesight is useless or the workshop manual assumes that the engineer knows where all this stuff is.

Thanks

[Rushjob]

Under the seat, just in front of the tool tray you wil see two relays fitted to the top of the mudguard.
The one on the right is the fuel injection relay, the one on the left the fan, that's taking left & right as if you were riding it........