I haven't had a chance to look at my car yet, but did pull out the wiring schematic for the early 911 (p. L-57 of the Workshop Manual). My copy shows a black/yellow wire going to terminal 53b on the Windshield Wiper Motor (component #52), whereas your first photo appears to show a black/green wire attached to that terminal. Is the 912 wiring perhaps different.
I'll take a look. I think that green stripe is 40 something year old yellow but I could be wrong.
If I remember correctly, (please note that these numbers are from a VW schematic, which should be similar) when you turn off the wipers, one of the 12V wires (53 or 53b I think) is supposed to go to ground, which is supposed to stop the motor in it's tracks (when it hits the park position). This ground connection is in the switch. Make sure your switch is properly grounded (pin 31). If that doesn't work, remove the switch and when in the off position, pins 31 and 31b should be shorted together and pin 31 should go to ground through a wire. (Google "1969 VW wiper motor schematic" and click on the first or second result that says "images").
Bob Brawders
Last edited by SIMI BOB; 04-23-2015 at 02:29 PM.
I'll look into that. Pulled my wires and hooked up another motor and put it on a blanket. It did the same thing. Wires are in the correct place. It appears to be either a bad wire(short/ground) or the switch I guess.
Chris
Is the red wire to term. 53a hot after the ignition is turned off.
Early S Registry member #90
R Gruppe member #138
Fort Worth Tx.
Yes it is. The speed when turned off is the same as the fastest position.
There should be constant power to 53a as it is what powers the park circuit. When the wiper switch is moved to the off position all other leads to the motor should be dead and then 53a powers the motor until it reaches the park position on the motor which then breaks the 53a circuit and it is parked. The wire positions should be 53a red (direct from fuse 4 which is always hot) 53b blk/yellow 53e blue and 53 blk/purp. Sounds like the first position is a fast rather than slow speed so the wiper motor always 'blasts' past the park position. Then again I could be all wet!! (pun intended)
Early S Registry member #90
R Gruppe member #138
Fort Worth Tx.
By any chance (1) are you having problems with your hi-lo head light control switch on the steering wheel column or the high beam indicator on the tach, or (2) does the problem only exist when your headlight hi-lo switch is set to one position or the other?
I open the wiper motor and the contact have oxide on one of the two connections and after cleaning those connection the motor work find again
The park function may be broken and doesnt know where to stop. The park terminal is always hot no matter where the switch is. You can disconnect the park wire and park the wipers with the switch.
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