Motor Will Not Run

Position panel switch in low-speed position. If motor can be heard running, check motor output shaft. If shaft is not turning, gearbox assembly requires replacement. If the shaft is turning, check drive link to output shaft for worn parts or disconnected components. If motor cannot be heard running, connect a voltmeter or test lamp between motor terminal "L" and ground.
If voltage is present and panel switch circuit breaker is not cycling, check for open ground circuit. Ground strap must make good contact. If motor runs, panel switch is not grounded, switch is faulty or there is an open in wiring. Common brush may not be making good contact with commutator and may require freeing-up or repositioning of spring. Armature may have an open circuit.
If voltage is present only part of the time, the circuit breaker is cycling. Problem may be a faulty circuit breaker or a short in the wiring, motor, or switch panel. Remove wiper arms and blades, disconnect harness at the motor and connect an ammeter between battery and terminal "L". If motor runs with average ammeter reading below six amperes, motor is good and trouble is in switch panel or wiring. If motor does not run and draw is more than six amperes, check wiper linkage for binding. Disconnect drive link from motor. If motor runs and draws less than three amperes, repair linkage. If motor fails to run or draws more than three amperes, check motor and gearbox for internal jamming. If no internal jamming exists, check motor for brush leads shorting to housing or armature for burned or blackened windings which could indicate an internal short.