Westerbeke 50 - Field Troubleshooting Tachometer;Hourmeter

SERVICE BULLETIN
V.ll
DATE:
BULLETIN NUMBER: 92
MODEL:
Apri 1 28, 1976
All
SUBJECT:
Troubleshooting Water Temperature and Oil Pressure Gauges
PIN:
Given a presumably faulty gauge indication with the instrument panel ener-
gized, the
first step is to check for 12 VDC between the ign. (8+) and
neg. (8-) terminals of the gauge.
Assuming there is 12 volts as required, leave the instrument panel ener-
gized
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 gauge tests are positive, the gauge is undoubtedly
O.K. 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 should be replaced.
Assuming the gauge is O.K., preoceed 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 O.K. and the engine block is grounded,
the sender
is probably defective and should be replaced.
21616
J. H. WESTERBEKE CORP.
AVON INDIJSTRIAL PARI<, AVON, MASS. 02322· (fS'7} 588-7700
CABLE: WESTCORP, AVON· TELEX: 92 - ........