Page 70 - Vauxhall 20-60 H.P. (R Type) Chassis Shop Manual

VAUXHALL 20-60 SHOP MANUAL

In these circumstances it may be advisable to increase the dynamo output.
The output is adjusted by altering the position of the third brush in relation
to the two main brushes.

Movement of the third brush is governed by a set screw ‘A’ at the terminal
end of the dynamo. Before this screw can be adjusted the locking screws
‘B’ must be slackened.

To increase the output ‘A’ must be turned in a clockwise direction, whilst to
reduce the output it should be turned anti-clockwise.

Make sure that the screws ‘B’ are finally tightened.

It should be remembered that the adjustment is a sensitive one, a small
movement of the third brush being sufficient to alter the output appreciably.
It is essential that the third brush should be re-adjusted to the original
setting when the car reverts to normal running conditions.

1
With the instrument board switch in the ‘ / 2 C’ position the charging rate is
sufficient to maintain the battery in a fully charged condition during the
summer months, when the lights are infrequently used.

CUT-OUT

SECTION To check the operation of the cut out accelerate the engine slowly and note
360 the ammeter reading on the instrument board. When the cut out closes,

the ammeter should begin to show charge. The pointer moving gradually
across the charge side of the scale as the engine speed increases. If when
the cut out closes the pointer jumps to a considerable charge or discharge,
it indicates that the cut out is not functioning correctly.

If with all switches ‘OFF’ the ammeter shows a discharge it indicates that
the cut out points are sticking. ( Provided that the ammeter pointer has not
been strained at any time due to a short circuit. )

If either of these conditions are evident the cut out should be replaced. In
removing the cut out disconnect the batter}’ before removing the leads
from the cut out.

RUNNING ENGINE WITH DYNAMO
DISCONNECTED

SECTION Serious damage will be done to the dynamo if the engine is run with
361 the dynamo disconnected, unless the positive terminal of the dynamo is
connected to earth.

DYNAMO BRUSHES

SECTION The three brushes should slide freely in their holders. If they do not it is most
362 probably due to the accumulation of dust and oil, and in these circumstances

they should be removed and cleaned. The brush springs should be inspected

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