Washer Fluid Level Switch: Operation

WARNING: This page is about a different car, the 2005 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.

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. (Refer to WASHER FLUID INDICATOR - DIAGNOSIS AND TESTING).