Relay Board Functions; Relay Board 1 (Rb1); Relay Board 2 (Rb2); Relay Board 3 (Rb3) - Komatsu 930E-2 Shop Manual

RELAY BOARD FUNCTIONS

The following describes the components and functions
of each relay board.

Relay Board 1 (RB1)

1 - Flasher Power Light (Green): This light will be
"ON" when the turn signals or hazard lights are
activated.
> K1 light will be "ON" during right turn signal op-
eration
> K2 light will be "ON" during left turn signal opera-
tion
> K3 light will be on when clearance lights are acti-
vated.
> K4 light will be flashing when the turn signals or
hazard lights are in operation.
NOTE: If circuit breakers (CB13 & CB15) are in the off
position, no warning will be noticed until the clearance
light switch is turned "ON".
1 - Flasher Module card.
3 - 15 amp circuit breakers (CB13, CB14, CB15)
4 - Relays
• Right Turn/Clear Light Relay (K1)
• Left Turn/Clear Light Relay (K2)
• Clearance Lights Relay (K3)
• Flasher Relay (K4)

Relay Board 2 (RB2)

1 - Data Storage Module card.
1 - Payload Stored Light (Green): This light is "ON"
for one second when the payload meter actually
stores the load data into memory.
1 - 5 amp circuit breaker (CB29) (To payload meter)
1 - 15 amp circuit breaker (CB28) (To payload lights
& relays)
4 - Relays
• Light Relay 1 (Green) (K1)
• Light Relay 2 (Amber) (K2)
• Light Relay 3 (Red) (K3)
• Light Control Relay (K4)
D03019 04/01

Relay Board 3 (RB3)

1 - Light Module Display card
1 - Rev Light (Green): This light is "ON" whenever the
selector switch is in the "reverse" position, and the
key switch is in the "ON" position.
4 - 15 amp circuit breakers
(CB16, CB17, CB18, CB19)
4 - Relays
• Manual Back-up Lights Relay (K1)
• Stop Lights Relay (K2)
• Retard Lights Relay (K3)
• Slippery Road Relay (K4) (Not used)
Relay Board 4 (RB4)
1- Steering Pressure Bleed Down Timer Module
card.
1 - Bleed Down Light (Green): This light is "ON" when
the bleeddown solenoid is being energized. The
bleeddown timer will energize the solenoid for 90
seconds after key switch is turned "OFF".
2 - 5 amp circuit breakers (CB20, CB22)
1 - 15 amp circuit breaker (CB21)
4 - Relays
• Park Brake Failure Relay (K1)
• Engine Cranking Oil Pressure Interlock Relay
(K2)
• Horn Relay (K3)
• Body Up Relay (K4)
Relay Board 5 (RB5)
1 - Light Display Module card
1 - Lights Control Light (Green): This light is "ON"
when 24 volts is being supplied to the battery
terminal of the light switch.
5 - 15 amp circuit breakers
(CB23, CB24, CB25, CB26, CB27)
4 - Relays
• Left Low Beam Relay (K1)
• Right Low Beam Relay (K2)
• Left High Beam Relay (K3)
• Right High Beam Relay (K4)
24VDC System Components D3-11