RAM 3500 Truck 2WD V8-5.7L VIN D (2003)
Backup Lamp Switch: Testing and Inspection
1. Disconnect and isolate the battery negative cable.
2. Raise and support the vehicle.
3. Locate and disconnect the engine wire harness connector for the backup lamp switch.
4. Check for continuity between the two terminal pins in the backup lamp switch connector.
a. With the gear selector lever in the Reverse position, there should be continuity.
b. With the gear selector lever in any position other than Reverse, there should be no continuity.