mtnman82

I'm wondering if my auto wipers stoppped working. I tried to test them by doing the following:

Engine on, all doors closed, auto transmission in park, parking brake on, wiper switch in position I (I believe this is the 'intermittent' position, where the sensor should do it's thing, correct?), driver's window open. I sprayed water on the windshield, on the sensor behind the rear-view mirror, but nothing. I got the wondow real wet, in fact but nothing. Then I went through checkginthe other positions (II & III) and they worked fine. I turned the switch to the off position, then to the intermittent position again, and this time the wiper worked at a steady intermittent pace?!?

Does the car need to be moving, or all windows up, or something (?) for the auto wipers to work?

Moviela

The I position is the correct place for the wipers to work automatically. The sensors are an Infrared transmitter and receiver. When the windshield is dry, it reflects almost all the light sent out by the transmitter. The receiver reports "dry" to the interior CAN, and nothing happens. A rain drop on the window causes the light to scatter and escape from the windshield. Less light falls on the receiver, and it tells the interior CAN "I feel wetness!"

Now, more water causes more scattering, and even less light falls on the receiver. This tells the CAN to run the wipers faster because it is wetter out there.

You can observe the transmitters with the switch in position II, there should be 4 little points of light. You can't see the infrared light with your eye, but if you have a video camera or a digital still camera point it at the windshield, and look on the screen. Most, but not all, eletronic cameras have at least some infrared sensitivity. You can also use this to view the light coming from the end of your key when you press and hold the open button.

mtnman82

Thanks for the tip on 'seeing' the IR signals. I'll definitely check that out.

Is there an easy way to check the auto wiper feature? I thought by having the car running with the wipers in the correct setting, and then spraying some water on the window, would set them off. Should this work? Maybe not??

MB-BOB

That should work. Also, when you first set the stalk in position Intermittant position, it should initiate a single wipe of the blades. If this does not happen, I would suspect the system is not working.

mtnman82

Thanks, MB-BOB. I thought it should. It does do the one wipe when I switch from 0 to I. And the dealer just had my car for 2 weeks. I guess I'll start another list with this and the climate control on it for what will probably be the last dealer service I will have done before the warranty expires.