300TD rear wiper
 

The rear wipers on both my 300TDs (84 & 85) don't work. Fuses are good, connections in the box are solid. Should I start checking the motors in the hatch or could I be missing something? The license plate lights and defroster in the hatch work fine.

Hi

Not sure what you mean by 'connections in the box'...........

When I discovered mine not working I went through same fault finding process replacing fuses, putting in new switch - but ended up (some 2 years later!!) sourcing unit from breakers yard.

When I got the old motor out the operating spindle (bit wiper connects to) was seized solid. I gave it to a chum who enjoys challenges a few months ago - and said see if you can sort this one out and it doesnt matter if you break it. Must chase him up - thanks for reminding me!!

It is my view water leaks down the spindle and if you have not used your wiper for a while the corrosion produces enough 'stiction' to prevent motor operating. If you do without for a while (in my case 2 years) it is then well and truly seized together.

If they worked on you cars recently take them out and get them on the bench you may be able to save them.

Good Luck

I'd check the terminal at the motor so you have power there.
The wiring could be broken near the hinge area.

Checked wiring in the gate. Get 12 volt positive on two pins on the connector and a good ground. Old motor turned a bit, then gave up. Replacement motor from the salvage yard doesn't work at all. Is there a relay I'm missing?

Does your 'new' motor turn freely by hand?

No, the “new” motor doesn't turn at all because of the worm gear assembly. The motor in the gate had been disconnected from the worm gear by the previous owner. It turned when I cleaned the plug contacts but wouldn't turn when I reassembled the gears. The new one doesn't hum and doesn't turn. You're not supposed to be able to turn the wiper by hand when the gears are engaged.