TP-6053 7/04 27Section 6 Controller Troubleshooting
Component Ohmmeter Connections Procedure Results
K1 Relay Coil K1 coil terminals
(see relay schematic)
OhmmeteronRx10
scale
If functional, approximately 270 ohms.
Low resistance (continuity), shorted coil.
High resistance, open coil.
K2 Relay Coil K2 coil terminals
(see relay schematic)
OhmmeteronRx10
scale
If functional, approximately 270 ohms.
Low resistance (continuity), shorted coil.
High resistance, open coil.
K3 Relay Coil K3 coil terminals
(see relay schematic)
OhmmeteronRx10
scale
If functional, approximately 400 ohms.
Low resistance (continuity), shorted coil.
High resistance, open coil.
K4 Relay Coil K4 coil terminals
(see relay schematic)
OhmmeteronRx10
scale
If functional, approximately 125 ohms.
Low resistance (continuity), shorted coil.
High resistance, open coil.
K5 Relay Coil K5 coil terminals
(see relay schematic)
OhmmeteronRx10
scale
If functional, approximately 510 ohms.
Low resistance (continuity), shorted coil.
High resistance, open coil.
Figure 6-2 Relay Testing
6.4 Controller Circuit Board
Some controller circuit board components can be tested
without removing the component from the circuit board.
Perform these checks prior to installing a new circuit
board and attempting startup. Use a high-quality
multimeter and follow the manufacturer’s instructions.
To obtain accurate readings when testing, remove all
the circuit board connectors and conformal coating
(transparent insulation) from component terminals. Use
the chart in Figure 6-2 and the controller circuit board
illustration in Figure 6-3.
The controller circuit board has light-emitting diodes
(LEDs) which indicate relay coil power and aid in the
circuit board and the generator fault detection. When
the K1, K2, K3, K4, or K5 relays receive power the
corresponding LED lights. The LED does not indicate
whether the relay coil is energized. Determine if the
relay coil is energized by analyzing the generator faults
when performing a continuity test on the relay coil.
H-239563
1
4
5
6
7
8
910
12
13
23
11
1. Engine crank control relay (K3)
2. P1 connector
3. P2 connector
4. Time delay relay (K5)
5. LED5
6. LED2
7. Engine run relay (K2)
8. AC crank disconnect relay (K1)
9. LED1
10. Fault shutdown relay (K4)
11. Relay schematic
12. LED4
13. LED3
Figure 6-3 Controller Circuit Board