Translate This Page
To do a basic test to establish that your dynamo is working :-
Lucas units
Disconnect the D & F (or F2) wires from it. Make a link wire up to connect
the 2 terminals together. Start the engine and raise the revs. Between the
common connection and the body of the dynamo connect a headlamp bulb (for a 6v dynamo
use a 6v 36w bulb and for a 12v dynamo use a 12v 60w bulb). The bulb should
light if the dynamo is good. Raise the revs and the bulb should burn brightly
and may even blow. Don't do this for too long as the dynamo is running
unregulated.
Bosch and other Continental dynamos/Dynastarters
Disconnect the wires D+ and DF. Connect the DF terminal to earth (DE). Connect a headlamp bulb across D+ and earth (DE) and run the engine. If the dynamo is good the bulb will light. Raise the revs and the bulb should burn brightly and may even blow. Don't do this for too long as the dynamo is running unregulated.