RAM 2500 Truck 2WD V8-5.9L VIN 5 HDC (1998)
4WD Switch: Description and Operation
Vehicles equipped with four wheel drive (4WD) have an indicator switch mounted on the front axle assembly. This switch is closed to ground when the
transfer case is shifted to four wheel drive mode and the engine is running on some vehicles. While in four wheel drive, the front and rear axles will
operate together. With this input, the CAB is able to modify its operation to allow for 4WD operation. Should a need for antilock operation occur while
in four wheel drive, the CAB will extend the amount of allowable dump cycles.