S-SERIES INSTRUMENTS
GAUGES
Except for air pressure, air restriction, and other optional
gauges which are mechanical Bourdon tube or
diaphragm-type all gauges are of the electromagnetic air
core-type. In each system to be monitored (Fuel Level,
Oil Pressure, Water Temperature, etc.), a sender uses a
variable resistance to control current from the battery
through a coil or coils in the gauge.
GAUGE TESTER
To assist in checking the electrical indicating-type
gauges, use of a universal-type Gauge Tester SE-2781
(Figure 16) is suggested. This test eliminates time-
consuming trial and error methods of checking out the
gauges.
Figure 16 Gauge Tester (SE-2781)
To test gauge operation, the sender wire is disconnected
from the sender unit and the tester is connected between
the sender wire and ground. The tester substitutes for
the sender unit as shown in Figure 17.
Figure 17 Gauge Tester Connections
Procedures for testing temperature, fuel level, and oil
pressure gauges with the gauge tester are given later in
this section. Tester setting and gauge reading
specifications are shown in Table 1.
NOTE - To ensure full power to all Instruments In
cluster, connector lock tabs on both sides of
harness connector must be solidly engaged with
cluster socket.
TABLE 1
GAUGE TESTER RESISTANCE SETTINGS (Ohms)
(For Use With SE-2781 Gauge Tester)
Gauge Reading
Type of Gauge
Low Scale
Half Scale
Full Scale
Water Temperature:
With 260° Gauge
1365
113
55
With 220 Gauge
1365
212
99
Fuel Level
1
44
88
Oil Pressure
1
47
88
Oil Temperature:
Engine
1365
63
28
Transmission
1365
63
28
Rear Axle
1365
63
28
CTS-4140Y Page 8
