677:3 Starter Relay Drive Circuit - Voltage Above Normal, or Shorted to High Source
The engine may or may not crank do to a faulty relay or wiring harness.
Note: This knowledge base article is not for the Skytrak machines with the 74 horsepower engines.
Starter Lockout Driver Circuit - Voltage Above Normal or Shorted to a High Source
Defective wiring harness
Bad Ground Connection
1. Locate the black box under the radiator. Then locate the fuse/relay panel which is the little black box inside the black box under the radiator.
1. Use a multimeter to verify there is continuity between pin 85 and 86 and replace if there is no continuity.
2. After verifying the starter lockout relay is good. Locate the J2 connector on the engine control module (ECM). The ECM is located on the firewall behind the engine and below the air cleaner. Access can be gained through the right engine door.
A. Unplug the J2 connector from the ECM. The J2 connector is the farthest from the back of the engine.
3. After locating and unplugging the J2 connector, using a multimeter, verify that the black wire label OUTPUT RTN 1 in pin 10 at the starter lockout relay plug has good continuity to pin 76 in the J2 connector.
A. If there is not continuity from pin 10 to pin 76, repair or replace the engine harness.
4. Perform a continuity test between pin 83 on the J2 connector and pin 1 at the starter lockout relay plug at the fuse/relay panel.
A. If there is not continuity from pin 83 to pin 1, repair or replace the engine harness.
5. If everything test good on the JLG side, then Cummins will have to test the ECM.
- Cummins Analyzer Kit
- Standard Mechanical Tools
- Fluke Multimeter