Introduction
The radiator fans are powered via a specific relay, which is enabled by the engine control unit.
Component assembling position

A injection relay; b etv relay (throttle valve actuator motor), c radiator fan relay, d engine control unit.

Location of right hand fan connection.

Location of left hand fan connection.
Connection wiring diagram

Ccm engine control connection, t radiator fan relay, a key on power (+15 from hands free relay 30), r battery power (+30), l left hand fan, r right hand fan, 85 light blue/black - lb/bk, 30 red/green - r/g, 86 red/black - r/bk, 87 red/grey - r/gr.
In the event of fault
In the event of a radiator fan relay fault, the radiator fans themselves do not work. The relay is not commanded by the ecu.
Fault codes generated and possible correlated faults fault codes generated by the engine control unit and displayed by the dds (fan relay diagnosis):
Note
Check integrity of electric circuit - short-circuit to vdc = with dashboard on, using a voltmeter, a voltage is measured between the wire tested and ground.
Check integrity of electric circuit - short-circuit to ground = with the battery cables disconnected, using an ohmmeter, continuity is detected between the wire tested and ground.
Check integrity of electric circuit - open circuit = with the battery cables disconnected, using an ohmmeter, no continuity is detected between the two ends of the wire tested.
The dashboard service display shows the error "fan relay" and the eobd warning light activates.
Possible correlated faults: coolant reaches boiling point but radiator fans not working. Check:
The radiator fan relay may be actuated from the dds to check radiator fan function.
The fans are normally activated at 103 and switched off at 101C.
If none of the aforementioned tests identify the problem and the radiator fan relay is in proper working order, replace the engine control unit.
Component replacement methods
No special measures are necessary in order to replace the radiator fan relay.
Starter motor relay
Engine speed-timing sensorOverhaul of cylinder head components
Cylinder heads
Remove any carbon deposits from the combustion chamber and its ducts.
Remove any scale from the coolant ducts.
Check for cracking and inspect the sealing surfaces for scoring, ridges or other
damage.
Check that the cylinder barrel mating surfaces of the cylinder head are ...
Abs diagnosis
Note
The on-screen icons used during this procedure are explained in a table at
the end of this section.
If the abs system is not working correctly, system diagnosis is possible
through the dds diagnosis instrument.
Turn on the dds diagnosis instrument (1) referring to the paragraph "tester ...
Indication of range reached for service
When service coupon threshold is achieved, upon every key-on the system
displays the indication of the type of
intervention that is required (oil service or desmo service).
The (red) warning is activated as a large icon for 10 seconds upon every key-on
(1) then as a small warning that
remai ...