Hey dudes,

When adjusting my interior mirror the other day I accidently touched the back of the rain sensor and activated the wipers. Now when I want the wipers to wipe once instead of flicking the wiper switch I simply touch the back of the rain sensor.

Anyone else tried this.

Cheers Firebird

 

I noticed the saem thing. Works great.

 

Thanks for the tip.

 

I found this out by accident while on the test drive.
Does anyone know exactly how the rain sensor works and why this tip works?
At first I thought it was something optical, but given the fact that touching it makes a difference, I'm now thinking it's some sort of electrical / magnetic principle...

 

Automatic operation

The wiper speed is determined by the amount of raindrops and sunlight detected by the automatic wiper control sensor.

Twist the automatic control adjuster in the “–” direction to lower the sensitivity, and the “+” direction to boost the sensitivity.

Even if the wiper lever is in the “AUTO” position, the system will switch to intermittent operations in the following conditions:

 When the windshield gets extremely cold (at less than –10C or 14F)

 When the system malfunctions

However, when the windshield gets extremely hot (at more than 90C or 194F), the wipers do not operate even if the wiper lever is in the “AUTO” position.

When the ignition switch is turned off with the wiper lever in the “AUTO” position, and then the ignition switch is turned on again, the automatic operation may not work even if raindrops are on the windshield.

In this case, move the lever to another position and return it to the “AUTO” position again.

 

I finally found the answer to my question about how the rain sensor works.
(Got it from http://techinfo.lexus.com.)

The rain sensor box contains 4 infrared LED's and 2 photo diode receivers. The unit works by bouncing infrared light off the windshield at an angle, and then measuring the amount of light that comes back. Raindrops on the windshield will alter the angle of reflection for the light, and therefore change the amount of light hitting the receivers.

Touching the unit must change the equation as well... maybe light that was getting "lost" ends up reflecting off your hand and affecting the measurement.