Atribuciones y Deberes de los Sistemas Municipales DIF:

The 24 VDC electrical system components shown in Figure 3-1 are accessed by unlatching the passenger seat base lid and tilting the passenger seat forward. The electrical schematics in Section R should be used when troubleshooting problems with the follow- ing components.

COMPONENTS

TAIL LIGHT RESISTOR DIODE ASSEMBLIES

The tail light resistor diode assembly RD1, RD2 (2, Figure 3-1) is a circuit designed to vary the intensity of each of the stop/tail lamp bulbs.

With the tail lights on, a resistor in series with the lamp reduces voltage supplied to the lamp, thereby reducing the lamp intensity. When the service brakes are applied and the stop lights are activated, current flows from the stop light relay, through a diode, bypassing the resistor and applies 24 VDC to the lamp filament.

RD1 controls the left lamp and RD2 controls the right lamp. No adjustments are available or necessary.

INCLINOMETER

The inclinometer (8) is used by the on-board load weighing system to determine whether the truck is on a level surface or tilted fore or aft. The information provided by the inclinometer is sent to the weighing system for use in calculating the payload. Refer to Section M for detailed information on the inclinome- ter and on board load weighing system.

BRAKE WARNING BUZZER (BWB)

The brake warning buzzer (11) provides an audible alarm for the operator if a malfunction occurs in the hydraulic service brake system. Refer to Section J for additional operational details.

LUBRICATION SYSTEM TIMER

Automatic Lubrication System lubrication interval is controlled by the timer (17, Figure 3-1). Lubrication cycle frequency can be adjusted by removing the timer cover and selecting one of five different timing intervals available. System “on” time is automatically determined by the timer and is not adjustable. Refer to Section “P” for additional automatic lubrication system details.

5 MINUTE IDLE TIMER COMPONENTS

The 5 minute idle timer circuit automatically provides approximately 5 minutes engine idle time before actual engine shutdown occurs. This system allows the engine cooling system to circulate coolant to reduce and stabilize engine component tempera- tures, when engine power requirements are minimal, resulting in extended engine life.

The circuit is controlled by a 3-position rocker switch. Pressing the bottom of the switch will turn the circuit OFF. The engine will shut down by use of the Key Switch, console mounted Engine Shutdown Switch, or the Ground Level Shutdown Switch.

With the rocker switch in the middle position, the cir- cuit is ON, but does not activate the 5 minute idle timer circuit. The engine can be shut down immedi- ately using any one of the three switches described above.

When the top of the switch is depressed and held momentarily, the idle timer circuit is activated. At the same time, the operator must turn the keyswitch to the OFF position. When released, the rocker switch will return to the ON (middle) position, and the 5 minute idle timer circuit is latched on through the switch. The amber “5 Minute Idle Timer” lamp in the overhead display will illuminate. The engine will then shut down after the 5 minute period.

However, if during the 5 minute idle timing sequence, the 5 minute delay switch (on the instrument panel) is pressed to the OFF position, the console shutdown switch is depressed, or the Ground Level Shutdown switch is activated, the engine will shut down immedi- ately, followed by the normal shutdown of all sys- tems.

D3-2 24VDC Electrical System Components D03027 FIGURE 3-1. PASSENGER SEAT BASE COMPARTMENT

1. Seat Base

2. Tail Light Resistor/Diodes (RD1/RD2)

3. Terminal Board (TB13) 4. Terminal Board (TB12) 5. Terminal Board (TB11) 6. 5 Minute Idle Timer 7. 5 Minute Idle Contactor 8. Inclinometer

9. Hoist Control

10. Compartment Service Light 11. Brake Warning Buzzer (BWB) 12. 5 Minute Idle Relay

13. Connector (RP226) 14. Connector (RP231) 15. Connector (RP230) 16. AID Module

17. Lube System Cycle Timer

18. Data Store Switch

19. Engine QUANTUM Diagnostic Port (Not Used)

20. Engine CENSE Diagnostic Port 21. Statex III Diagnostic Port 22. Spare Connector Location

D03027 24VDC Electrical System Components D3-3

5 Minute Idle Timer

The 5 minute idle timer (6) circuit is activated when the operator presses the 5 minute idle timer engine shutdown switch mounted on the instrument panel. (This is a momentary switch that also latches the 5 minute idle timer in the energized position.) When the timer is energized, internal contacts close and ener- gize the relay and contactor described below.

5 Minute Idle Relay

The relay (12) contacts close when the idle delay timer is energized. When the contacts are closed, the AID system indicator light circuit (12M) is grounded through the “5 minute idle timer” indicator lamp on the overhead display, turning the lamp on.

5 Minute Idle Contactor

The contactor (7) energizes the idle timer and main- tains current flow to the engine “run” circuit if the operator turns the key switch off.

5 MINUTE IDLE CIRCUIT TEST

Check 5 minute idle timer circuits as follows:

1. With the key switch ON, press the Engine Shut- down switch firmly to the momentary position and release (switch will return to the ON posi- tion).

2. Turn the key switch OFF and verify the follow- ing:

Y Circuit 712 (to ground) remains 24 volts for approximately 5 minutes. After 5 minutes, the voltage drops to 0.

Y The 5 minute idle indicator lamp on the overhead display is ON when circuit 712 reads 24 volts.

3. Repeat step 1. While monitoring voltage at cir- cuit 712, turn the key switch OFF. Turn the engine shutdown switch off.

Y Verify voltage at circuit 712 drops to 0 when the shutdown switch is turned to OFF.

DATA STORE SWITCH

The Data Store switch (18) allows a technician to store propulsion system event data during truck operation while troubleshooting the system. Refer to Section “E” for additional information.

KOMATSU ENGINE QUANTUM CONNECTOR (Not Used)

This connector (19) is for use by qualified personnel to access engine diagnostic information for the QUANTUM system. Refer to engine manufacturer’s service publications for troubleshooting information.

KOMATSU ENGINE CENSE CONNECTOR

This 3-pin connector (20) is for use by qualified per- sonnel to access engine diagnostic information for the CENSE system. Refer to engine manufacturer’s service publications for troubleshooting information.

STATEX III PROPULSION SYSTEM DIAGNOSTIC