OEM Rain Detection Module for Automatic Wipers ☔

Why this part is needed

This smart windshield module keeps your view clear without touching the stalk. It starts and varies the wiper speed automatically when rain hits the glass. Safer night driving, less distraction in traffic, and longer wiper blade life. Great for comfort, but also a real safety add-on when weather changes fast .

How it works

The unit uses infrared light and a photodiode behind the rearview mirror. On dry glass, light reflects predictably; water drops scatter it. The controller reads that change, talks to the body ECU or wiper relay, and sets wipe intervals from gentle sweep to continuous. A clear gel pad couples the sensor to the windshield; correct alignment and a clean surface are essential .

What happens if it’s broken

Typical signs: no auto-wipe, random single wipes on dry glass, intermittent speed stuck, or a warning in the cluster. In heavy rain you’ll react slower, visibility drops, and blades may chatter. A failed gel pad causes poor sensitivity; a shorted unit may drain battery. Many faults are fixed by recalibration after glass work; hard faults require replacement .

Install notes

Use a new optical gel pad, degrease the glass, align guide marks, press evenly, and run calibration with a scan tool if required. Avoid bubbles and do not touch the lens.

Compatibility

• Land Cruiser