Usage:
All Machines So Equipped
Reference: Service Magazine; May 26, 1986; Page 5; "Wiper Motor Grounding."
All Bosch wiper motors, like 6T6216, 3T0189 and 6T6529, with four wires and a Sure-Seal® connector use one wire for high speed, one wire for low speed and two wires for "parking". The motor is grounded electrically through a motor-to-cab mounting. A good ground is required for correct operation.
NOTE: All voltage measurements are made with respect to motor case (housing).
The following troubleshooting includes most wiper problems.
Problem 1. Motor is dead or intermittent in either speed.
Solution: Check ground connection as per reference article.
Problem 2. Motor is dead or intermittent in only one speed.
Solution: Check wiring from switch speed connection to motor side of four-pin motor Sure-Seal connector. If voltage (system) is present at motor but will not run, replace the motor.
Problem 3. Motor runs in both speeds but will not park.
Solution: While parking, all parking wiring and park switch should be at system voltage and connected to the low speed wiring. If not, find the break with a continuity meter (6V7070 Multimeter Group, or equivalent).
NOTE: The illustrations are for a Challenger 65 Tractor, but the method of wiring is typical for all machines so equipped.
Illustration 1. Low speed.
Illustration 2. High speed.
Illustration 3. Wiper parking.
Illustration 4. Wiper parked.