4-50 4181384 First Edition
ELECTRICAL
4
Troubleshooting
Power Circuit
Symptom: No power to cab connector.
Symptom: No power to accessory socket.
Symptom: Fuel pump does not operate.
Symptom: Control module does not power
up.
Probable Cause Remedy
Open fuse 40A fuse F11. Test fuse. (See “Fuse Test” on page 4-61.)
Probable Cause Remedy
Open fuse 15A fuse F2. Test fuse. (See “Fuse Test” on page 4-61.)
Probable Cause Remedy
Open fuse 7.5A fuse F7. Test fuse. (See “Fuse Test” on page 4-61.)
Faulty fuel pump switched power circuit. With the key switch in the run position, measure voltage between fuel pump grn wire
terminal and ground. Voltage must be approximately 12 VDC.
Open fuel pump ground circuit. Check continuity between fuel pump blk wire terminal and ground. Continuity must be
indicated.
Faulty fuel pump. Replace fuel pump.
Probable Cause Remedy
Open fuse 10A fuse F10. Test fuse. (See “Fuse Test” on page 4-61.)
Faulty control module switched power
circuit.
With the key switch in the run position, measure voltage between control module terminal
3 and ground. Measure voltage between control module terminal 8 and ground.
Voltage must be approximately 12 VDC.
Open control module ground circuit. Check continuity between control module terminal 1 and ground. Continuity must be
indicated.
Faulty control module. Substitute the control module with a known good control module.