Windshield glass and wiper blade elements may become contaminated by wax left on the glass, after a car wash and can cause chattering wiper blades and/or uneven wipe
To correct this condition, clean both windshield glass and rubber blade elements as follows:
1. Clean windshield glass with a glass cleanser that will not harm the paint finish or scratch the windshield. One such product that can be used is the Bon Ami "Cleaning Powder". The glass is clean when the rinse water no longer "beads-up" but "sheets" across the entire glass surface.
2. Clean wiper blade elements using a cloth or towel that has been saturated with a solution of 50% water and 50% GM Opti Kleen or a solution of 50% water and 50% methanol alcohol. Rinse the wiper blade with water and reinstall on the wiper arm.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.