Ducati SPORTTOURING ST3 Manuel D'utilisation page 172

Turn indicators
The bulbs of the turn indicators are accessible after
removing the instrument panel side guards.
Front:
Turn the bulb holder (1, fig. 80) anticlockwise and remove
it from indicator body. Withdraw the burnt-out bulb and
replace it.
Refit the bulb holder with the round slot pointing upward
E
and turn it clockwise until it locks in place in the indicator
body.
Rear:
remove the screw (2, fig. 81) and detach the glass (3) from
the indicator body holder.
The bulb is of the banjo-type: press and rotate
anticlockwise to remove; fit the spare bulb by pressing and
turning clockwise until it clicks. Refit the glass sliding the
small tab (A) into the suitable slot in the indicator body
and tighten the screw (2).
72
1
OPEN
CLOSED
A
3
fig. 80
2
fig. 81