S SERIES INSTRUMENTSVOLTMETER(BATTERY/CHARGING SYSTEM GAUGE)OperationThe voltmeter or battery/charging system gauge (Figure24) indicates the condition of battery and chargingsystem. This gauge will monitor a voltage rangebetween 10 and 16 volts. Color segments of this rangealso indicate system condition as follows:GREEN - A well-charged battery.FIRE ORANGE - Either a too high or too lowcharged battery.Figure 24 - Voltmeter Circuit DiagramWith key switch "on" but before starting engine, thevoltmeter will show condition of battery. While startingengine, indicator will temporarily descend to "FireOrange" segment but immediately return to "Green"segment when engine is operating. With engine runningat operating speeds, the voltmeter indicator shouldremain in the "Green" segment. This is chargingsystem’s nor-mal operating range and indicatesalternator is charging.If indicator ascends to "Fire Orange" segment, alternatorvoltage output is too high.Constant reading in either high or low "Fire Orange"segments of the voltmeter indicates a complete check ofbattery and charging system is required. Seeappropriate alternator section of the Service Manual.TestingOperation of voltmeter can be checked by removingvoltmeter from cluster and connecting voltmeterterminals to an independent voltage source (12 Vbattery). The voltmeter should indicate battery voltage 05 volt.If voltmeter reads properly, voltmeter is OK andproblem is in vehicle wiring. Check continuity with testlight.If voltmeter does not read properly, replace voltmeter.EXHAUST PYROMETERDescriptionThe exhaust pyrometer indicates the temperature ofexhaust gases leaving the engine.The exhaust pyrometer system (Figure 25) consists ofthe dash unit (gauge) mounted on the instrument panel,the sender unit (thermocouple) mounted in the engine’sexhaust outlet and the connecting wiring circuits.Figure 25 - Pyrometer TestsCTS-4140Y - Page 14
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
