Some pulse permanent magnet depressed park wiper motors (build dates approx. 200-4 through 115-85) may exhibit intermittent starting conditions in pulse mode.
This condition may be due to a build up on the commutator. Do not rap on motor to correct this condition. The end cap (P/N 22038791) must be replaced per the following procedure:
a. Disassemble end cap by bending fasten tabs outward and remove end cap from armature shaft (see Figure 1). Do not remove armature.
b. Spray electrical contact and tape head cleaner or equivalent on clean cloth and wipe commutator clean. Apply supplied grease to end of armature shaft.
c. Install new end cap and bend fasten tabs back to original position.
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.