Instruments and Controls Identification Oil Pressure * NOTE: A pyrometer is set to ambient tempera- ture. When the engine is cold, the pyrometer indicates the approximate outside temperature. Do not attempt to adjust the pyrometer to zero degrees. Engine Model Idle Speed: psi (kPa) Rated Speed: psi (kPa) Cummins L10 10 (69) min. 35 to 45 Cummins NTC 10 (69) min. 35 to 45 (241 to 310) Voltmeter (241 to 310) Cummins C Series 10 (69) min. 30 (207) Detroit Diesel 12 (83) 50 (345) min. The voltmeter ( Fig. 2.27 ) indicates the vehicle charg- ing system voltage when the engine is running and the battery voltage when the engine is stopped.
By monitoring the voltmeter, the driver can be aware of potential charging system problems and have them fixed before the batteries discharge enough to create starting difficulties. * Oil pressures are given with the engine at operating temperature. With the engine cold, oil pressure may be higher. Individual engines may vary from the listed pressures; observe and record pressures when the engine is new to serve as a guide for check- ing engine condition. Table 2.3, Oil Pressure CAUTION 1 2 3 A sudden decrease or absence of engine oil pressure may indicate mechanical failure. Bring the vehicle to a safe stop, and investigate the cause to prevent further damage.
Do not operate the engine until the cause has been determined and corrected. 4 5 Pyrometer, Optional A pyrometer ( Fig. 2.26 ) registers the exhaust tem- perature near the turbocharger. Normal exhaust tem- peratures are listed in Table 2.4 . Normal Exhaust Temperature Engine Model °F (°C) Caterpillar C-10, C-12 935 to 1290 (500 to 700) Caterpillar C-15 950 to 1050 (510 to 566) Cummins L10 800 to 1000 (430 to 540) Cummins NTC 750 to 950 (400 to 510) Cummins C Series 1290 (700) max. Detroit Diesel 700 to 950 (370 to 510) 01/18/95 f600511 1. Application Air Pressure Gauge 2. Dual System Air Pressure Gauge 3. Voltmeter 4. Fuel Gauge 5. FloScan Fuel-Tach Fig.
2.27, Air Pressure, Fuel Gauges, and Voltmeter The voltmeter will normally show approximately 13.7 to 14.1 volts when the engine is running. The voltage of a fully charged battery is 12.7 to 12.8 volts when the engine is stopped. A completely discharged bat- tery will produce only about 12.0 volts. The voltmeter will indicate lower voltage as the vehicle is being started or when electrical devices in the vehicle are being used. Table 2.4, Normal Exhaust Temperature Variations in engine load can cause exhaust tem- peratures to vary. If the pyrometer reading shows that exhaust temperature exceeds normal, throttle less fuel to the engine until the exhaust temperature is reduced.
Shift to a lower gear if the engine is over- loaded. If the voltmeter shows an undercharged or over- charged condition for an extended period, have the 2.26