Westerbeke WPDS-20 Technical Manual page 112

WESTERBEKE
MARINE ENGINE PRODUCTS
SERVICE BULLETIN 92
ISSUED: April 28, 1976
SUBJECT: Troubleshooting Water Temperature and Oil Pressure Gauges
MODELS: All
DISTR: Distributors, Shipments
Given a presumably faulty gauge indication with the instrument panel
energized, the first step is to check for 12 VDC between the
ig~
(8+) and
neg. (8-) terminals of the gauge.
Assuming there is 12 volts as required, leave the instrument panel energized
and perform the following steps:
1. Disconnect the sender wire at the gauge and see if the gauge
reads zero, the normal reading for this situation.
2. Connect the sender terminal at the gauge to ground and see
if the gauge reads full scale, the normal reading for this
situation.
If both of the above gague tests are positive the gauge is undoubtedly OK
and the problem lies either with the conductor from the sender to the gauge
or with the sender.
If either of the above gauge tests is negative, the gauge is probably
defective and shou1d be replaced.
Assuming the gauge is OK, proceed as follows. Check the conductor from the
sender to the sender terminal at the gauge for continuity.
Check that the engine block is connected to ground. Some starters have
isolated ground terminals and if the battery is connected to the starter
(both plus and minus) the ground side will not necessarily be connected to
the block.
If the sender to gauge conductor is OK and the engine block is grounded,
the sender is probably defective and should be replaced.
PIN 21616
4/28/76
V13
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