PIAGGIO 633929(IT), Service Station Manual, Page: 79 / 314

Recharge system voltage check
Connect an ammeter induction clamp to the volt-
age regulator positive terminal, measure the bat-
tery voltage and turning on the vehicles lights with
engine off, wait for the voltage to set at about 12
V. Start the engine and measure the current gen-
erated by the system with lights on and a high
running engine.
In case the generated current value is lower than
10A, repeat the test using a new regulator and/
stator alternatively.
Choke Inspection
Refer to the engine section to check the resistance
and operating conditions of the component. As re-
gards voltage supply, keep the connector connec-
ted to the system and check that the two terminals
receive battery voltage when the engine is on (see
figure).
If voltage is detected, replace the automatic starter
as it is surely failing.
If no voltage is detected, connect the multimeter
negative terminal to the earth terminal and the
positive terminal to the automatic starter orange
cable; with the key switch set to «ON» check
whether there is battery voltage; if there is no volt-
age, check the wiring connections to the key
switch and that the 15A fuse works properly.
If there is voltage, check again the ignition control
unit connector. After disconnecting the starter,
start up the engine and keep it at idle speed; then
check there is voltage connecting the multimeter
MP3 125
Electrical system
ELE SYS - 19