GMC Motorhome Electric Windshield Wiper Conversion
Welcome to the GMC Wipers Etc web site, created to offer you more information about the kit I offer for replacement of the 73-78 GMC motorhome’s hydraulic windshield wiper motor with an electric motor.
The kit consists of a mounting bracket which mounts in place of the original hydraulic motor using the same three bolt holes. The bracket provides an idler arm which exactly duplicates the location and motion of the original arm on the hydraulic motor. Some additional adjustability is provided for minor improvement of the wiper arm motion. All of the steel components are CNC machined and black powder coated. The various bushings, ball joints, etc., are readily available hardware items in the unlikely event of any failure; sources are provided.
The mounting plate for the motor is specifically designed for the 90-96 Chevrolet Lumina APV / Olds Silhouette / Pontiac TranSport wiper motor because that motor is designed to swing long arms with 24" blades and has internal circuits to provide intermittent (pulse) operation and 3 second wipe-with-wash. It is also directly compatible with the steering column mounted combination switches used on later model (80\90's) GM vehicles. Mounting holes are provided for other motors, such as the Saturn motors widely available from surplus dealers and for common bus/RV motors. It should be easy to adapt almost any motor with a 360* rotating output shaft. But, I have not tested any other motor nor do I know anything about wiring them. Please share the details if you do use a different motor.
With the mechanical kit, I include all of the necessary hardware to replace the hydraulic motor except for the wiper motor and electrical components. On some vehicles it may be necessary to re-route or extend the power steering fluid return hose which is moved from the wiper motor to the power steering gear box; that added hose is not provided. The hose fittings to connect the return hose to the gear box are included. The kit includes detailed step-by-step installation instructions for the kit, conversion to the steering column mounted switch, and harvesting of Lumina motors.
To simplify the onerous task of wiring the switch, pulse delay rheostat, and electric motor, I offer pre-wired harnesses with one of three switches: Toggle, Rocker, or Push-to-Wash/Turn-to-Wipe (PtW/TtW). The PtW/TtW is most popular because it can replace the original washer switch and has a Washer/Wiper logo on the face of the black knob. To ease installation, the harness wires are unterminated at the motor end; crimp connectors are provided for application after the wires are routed through the firewall and cut to length. All components, including a 25A circuit breaker, are included EXCEPT the 5-pin connector which plugs into the motor. That absurdly expensive item is best purchased at a junk yard with the motor (which is needed for trade-in even if you purchase a rebuilt motor).
The toggle and rocker switch harnesses are $50 each; the PtW/TtW $75. I do have a few of the motor connectors available for $10 each. Again USPS shipping is included.
I DO NOT sell wiper motors. The motor is so reliable, and usually so easy to repair if it does fail, that I recommend purchasing a used one, with connector, from a junk yard. In my experience the price should be $20-$25. It would make no sense for me to collect motors, clean them, test them, and ship them across country; I’d have to charge $50, or more if I offered a warranty.
Rebuilt motors with lifetime warranty are available; it’s a standard stock item at AutoZone for about $70-$80, plus core (get it at the junkyard WITH the connector). Or a new motor can be bought from www.RockAuto.com, among others, for about $130. New connectors are available there also for about $30. Again, it would make no sense for me to purchase those motors and ship them across country at a marked up price – the warranty would be in my name, not yours, so you couldn’t walk into a parts store and get a free replacement.
The following links will guide you to additional information to help you decide whether this is what you need: