GM Service Manual Online
For 1990-2009 cars only

The band on the wiper lever with the smaller arrow operates the rear wiper/washer.

(Off): Turn the band to this position to turn off the rear wiper.

(Rear Wiper): Turn the band with the smaller arrow to this position to turn on the rear wiper. To set for a shorter or longer delay between wipes, turn the other band with the larger arrow pointing to the numbers (1, 2, or 3). Select 3 for the most frequent movement; select 1 for the least frequent. The band with the arrow pointing to the numbers (1, 2, or 3) will affect both the front and rear wipers if they are on at the same time.

(Wash): Turn and hold the band in this position to spray washer fluid on the rear window. The rear wiper will also come on. Release the band when enough fluid has been sprayed on the window. The rear wiper will run a few additional times after you release it.

The rear window washer uses the same fluid bottle as the windshield washer. However, the rear window washer will run out of fluid before the windshield washer. If you can wash your windshield but not your rear window, check the fluid level.