Checking cable to wiper motor
The rain sensor needs a signal from the wiper motor in order to function. The signals are used by the rain sensor to calculate when the next stroke should be made.
A non-functioning rain sensor can cause the windshield wipers to remain stationary in the parked position when the intermittent function is switched on but to function normally in the low and high speed positions. This can also appear as if the rain sensor does not sense water on the windshield and does not wipe the windshield clean.
Causes of non-function can be:
- A crack in the glass so that the sensor cannot detect rain
- The rain sensor does not have sufficient contact with the windshield
- Defective rain sensor.
Checking the wiper motor cable
Check the cable to the wiper motor for defects. Check that the wiper motor is connected to terminal #4 on the rain sensor. Check that the wiper motor registers the position of the windshield wiper on the screen.
HINT: There is probably oxidation on terminal #4 of the rain sensor because a small voltage runs through it.
Checking contact with the windshield
When removing and reinstalling the rain sensor it is very important that a complete contact with the windshield is achieved. There is a silicon layer which must lie completely against the windshield around the rain sensor. This is so that the light from the rain sensor can detect when there is rain on the windshield. Rectify the problem by removing the rain sensor. Check the mating surface and then reinstall the rain sensor.
Remedy as necessary