Liberty 4WD L4-2.8L DSL Turbo VIN 5 (2006)
Washer Fluid Level Switch: Description and Operation
WASHER FLUID LEVEL SWITCH
DESCRIPTION
The washer fluid level switch is a single pole, single throw reed-type switch mounted just above the sump area near the bottom of the washer reservoir.
Only the molded plastic switch mounting flange (1) and the integral connector receptacle (5) are visible when the switch is installed in the reservoir. A
short nipple formation (4) extends from the inner surface of the switch mounting flange, and a barb on the nipple near the switch mounting flange is
pressed through a rubber grommet seal installed in the mounting hole of the reservoir.
A molded plastic float (3) rides saddle-like over a molded plastic beam that extends axially from the switch mounting flange. A small permanent magnet
(2) is secured in a receptacle on the top of the float, and the reed switch is concealed within the beam. A diagnostic resistor is connected between the two
switch terminals within the switch mounting flange. The washer fluid level switch cannot be adjusted or repaired. If inoperative or damaged, the switch
must be replaced.
OPERATION
The washer fluid level switch uses a float to monitor the level of the washer fluid in the washer reservoir. The float contains a small magnet. When the
float moves, the proximity of this magnet to a stationary reed switch within the beam formation of the switch changes. When the fluid level in the washer
reservoir is at or above the float level, the float rises and the influence of the float magnetic field is removed from the reed switch causing the normally
open reed switch contacts to open. When the fluid level in the washer reservoir falls below the level of the float, the float falls and the influence of the
float magnetic field is applied to the reed switch, causing the contacts of the normally open reed switch to close.
The washer fluid level switch is connected to the vehicle electrical system through a dedicated take out and connector of the headlamp and dash wire
harness. The switch is connected in series between ground and the washer fluid switch sense input to the ElectroMechanical Instrument Cluster (EMIC).
The switch receives a path to ground at all times through another take out of the headlamp and dash wire harness with a single eyelet terminal connector
that is secured under a ground screw near the front of the left front fender inner shield in the engine compartment. When the switch closes, the EMIC
senses the ground on the washer fluid switch sense circuit. The EMIC is programmed to respond to this input by illuminating the washer fluid indicator
and by sounding an audible chime tone warning.
The washer fluid level switch input to the EMIC may be diagnosed using conventional diagnostic tools and methods.
