RAM 2500 Truck 2WD V10-8.0L VIN W (2003)
Windshield Washer Pump: Description and Operation
Fig.12 Washer Pump/Motor
WASHER PUMP/MOTOR
The washer pump/motor unit is located on the rearward facing surface of the washer reservoir, in the right (except V-10 or diesel engine) or left (V-10
and diesel engine only) front corner of the engine compartment. A small permanently lubricated and sealed electric motor is coupled to the rotor-type
washer pump. A seal flange with a barbed inlet nipple on the pump housing passes through a rubber grommet seal installed in a dedicated mounting
hole of the washer reservoir. When the pump is installed in the reservoir a barbed outlet nipple on the pump housing connects the unit to the washer
system through a short washer reservoir hose.
The washer pump/motor unit is retained on the reservoir by the interference fit between the barbed pump inlet nipple and the grommet seal, which is a
light press fit. The top of the washer pump is also secured to the washer reservoir by the use of a snap post on the motor housing and a snap post
receptacle molded into the reservoir that allows for mounting of the washer pump without the use of fasteners. An integral connector receptacle on the
top of the motor housing connects the unit to the vehicle electrical system. The washer pump/motor unit cannot be repaired. If faulty or damaged, the
entire washer pump/motor unit must be replaced.
The washer pump/motor unit features a small Direct Current (DC) electric motor. The motor is connected to the vehicle electrical system through a
single take out and two-cavity connector of the right (except V-10 or diesel engine) or left (V-10 or diesel engine only) headlamp and dash wire
harness. The motor is grounded at all times through another take out of the right (except V-10 or diesel engine) or left (V-10 or diesel engine only)
headlamp and dash wire harness. On models without the V-10 or diesel engine a single eyelet terminal connector is secured by a nut to a ground stud
located on the right front fender inner shield in the engine compartment. On models with a V-10 or diesel engine an eyelet terminal connector is
secured by a ground screw to the left front fender inner shield in the engine compartment. The motor receives battery current on a washer pump/ motor
control circuit.
The washer pump/motor control circuit is energized through a high side driver within the Front Control Module (FCM) whenever the FCM receives an
electronic message requesting washer system operation from the instrument cluster over the Programmable Communications Interface (PCI) data bus.
The instrument cluster monitors a resistor multiplexed hard wired input from the momentary washer switch contacts within the multi-function switch
on the steering column to determine when it should issue the electronic message requesting washer system operation.
Washer fluid is gravity-fed from the washer reservoir to the inlet side of the washer pump. When the pump motor is energized, the motor spins the
rotor within the washer pump. The spinning pump rotor pressurizes the washer fluid and forces it through the pump outlet nipple, the washer
plumbing, and the washer nozzles onto the windshield glass.
The washer pump/motor unit may be diagnosed using conventional diagnostic tools and methods.
