THE LAMP CIRCUIT
The head and aide lamps are double-wired to the
connector blocks under the bonnet.
BODY LAMP CIRCUIT.
Closed bodies have their roof lamps wired directly to the battery via the, junction box on the chassis frame, under the floor boards. There is a fuse in this junction box.
THE RED LAMP.
The red lamp on the instrument board is a shunt between the positive of the battery and the positive of the dynamo. If the dynamo is not charging, battery current can flow through the lamp to earth, via the dynamo. The lamp goes out automatically when the dynamo cuts in, and this is a useful indication that the dynamo is action. The going out of the red lamp, however, is not a sign that the battery is no longer discharging: it is merely a sign that the dynamo is contributing directly to the circuit as much current as its speed permits. If the total current consumed is in excess of the total output of the dynamo, the ammeter will indicate discharge although the red lamp is out. The lighting up of the lamp is not dependent upon any actual flow of current in the ignition circuit, and is not in any way a test of it. The red lamp should always go out when the engine is accelerated. If it does not do so, immediate attention should be paid to the fuse, terminal contacts, dynamo brushes and commutator.
REPLACING LAMP BULBS
Always switch off when replacing lamp bulbs; there is
no fuse in the lamp circuit. Hold the bulb in a cloth to
protect the hand in the event of breakage.
SIDE AND TAIL LAMPS.