Rear Wiper Sticks
 

The rear cwiper on my GV has started to stick in the 'half wipe' position. i.e. I switch the wiper on, it makes a 180 deg sweep then sticks on it's return travel. When it sticks the motor starts humming until I give it a gently push with my hand. It's as if the motor hasn't got enough power to start the return sweep. Has anybody experienced this?

LUBE the SPINDLE!

Worth a try I suppose. I'll let you know the outcome.

Be liberal with lube that you use(penetrating oil, spray lubes, oil squirt can),, protect window and paint surfaces, and help it along with a little helping hand power as it soaks in to the spindle. after 23 years of driving these vans(at least 6 by now) the rear wiper spindle is a weak spot, but I have only lost 1 rear motor from this common happening.

With normal wiper motors the park contacts are in the unit itself but from a previous thread someone said the park unit was exterior. Still to be clarified this.

I'll let you know what I uncover if I need to go as far as stripping the motor down Goggsy. My first thought was the limit switch but the wiper blade does return with a gentle nudge. It's possible that the limit switch also reverses the voltage supply and because the polarity isn't switching, the motor just hums when it reaches its physical stop.

AGAIN clean/lube the rear wiper SPINDLE. BTDT!!

I lubricated the wiper spindle with machine oil (3 in 1) to no avail. So I removed the wiper arm, after making a puller to pull it off the spindle, and then lubricated the spindle with the motor running continuously. The spindle moves 180 degrees and returns without hesitation, even if I induce resistance by gripping it with my fingers. So after leaving it running while adding lubricant for 10 minutes or so, when I put the wiper arm back onto the spindle it stalls at the 180 degree point. I'll leave the arm off for a few days to allow the lubricant to penetrate further but I suspect that either the gears are worn or the commutator brushes need replacing.

I usually use a penetrating oil or cutting oil to break up the corrosion that form between the spindle shaft and housing, but a lot depends on how long lubrication has been neglected. The resistance there make the motor work harder..reducing it's lifespan. Amazing how that area is prone to the "elements". I lube up the rear spindle of mine 2X a year.

I finally got round to investigating my rear wiper problem more thoroughly. After dismantling the motor assembly I discovered that the main drive gear, which is made from nylon, is worn away in the area at the exact point where it reverses rotation. The assembly doesn't use limit switches, just a clever design of the steel gears to switch direction of the output shaft, and a break point in the electrical contact plate for the park position. See the attached photo's for a better understanding.