Dodge Ram Truck 1500-2500-3500. Manual - part 605
PUMP-WASHER-WINDSHIELD
DESCRIPTION
The washer pump/motor unit (1) is located on the
rearward facing surface of the washer reservoir, in the
right (except SRT-10 and diesel) or left (SRT-10 and
diesel 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 (6) on the
pump housing passes through a rubber grommet seal
installed in a dedicated mounting hole of the washer
reservoir. A removable molded plastic filter screen (7)
inserted into the inlet nipple prevents most debris from
entering the pump housing. When the pump is
installed in the reservoir a barbed outlet nipple (5) 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 nip-
ple 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 (2) 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 (3) 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.
OPERATION
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 SRT-10 and diesel)
or left (SRT-10 and diesel only) headlamp and dash wire harness. The motor is grounded at all times through
another take out of the right (except SRT-10 and diesel) or left (SRT-10 and diesel only) headlamp and dash wire
harness. On models except SRT-10 or diesel, 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 SRT-10 or diesel models, an
eyelet terminal connector is secured by a ground screw to the left front fender inner shield in the engine compart-
ment.
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 elec-
tronic message requesting washer system operation from the ElectroMechanical Instrument Cluster (EMIC) over the
Programmable Communications Interface (PCI) data bus. The EMIC 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. However, con-
ventional diagnostic methods may not prove conclusive in the diagnosis of the EMIC, the FCM, the PCI data bus or
8R - 60
WIPERS/WASHERS - SERVICE INFORMATION
DR/DH