wiper speeds inactivated after painting

randywebb · 03-19-2006, 10:19 AM

I just got my 1973.5 911 back from the paint shop and wipers only work at a single speed. I know he took the wiper arms off but that shouldn't affect this. The wipers park fine and work at each 'on' position of the switch - but each on gives the same speed.

I wonder if his messing with the seals for the arm spindles could have created too much friction or something?

Or maybe the huge amounts of paint and filler dust he elft all over the trunk got into the wiper motor - or maybe the switch on the steering column?

Looking at the electrical diagrams, there is only a single blue (25 amp) fuse, so a missing fuse can't be the problem.

The switch, (#30 on the diagram), has Arabic numerals 0, 1, 2 at the far right, then next to that are Roman numerals 0, I, II, III - so I'm not sure what that is supposed to mean...

The wiper motor (# 73) is pretty hard to figure out - I can see the rotating wiper park wheel on the diagram but that's about all I can figure out. Any idea which wires I might be able to jump together to see if the motor will produce different speeds? Besides Red?white (from the fuse & an ext. jumper of the same colors) and bsides the Brown ground wire, I have 3 others on the motor diagram - Blue, Black/Yellow, and Black/Purple.

I'm not sure if this car had interval wipers - it's been out of service so long I can't remember(!)

HarryD · 04:19 PM

Randy,

My 73.5 does not have interval wipers. I have no clue about what the Arabic and Roman numerals mean but I think the Arabic ones are for the washer and the Roman ones are for the windshield wiper positions.

Looking at the wiring diagram, it appears that there is a resistor pack inside the wiper motor and the switch is used to select the amount of resistance. It looks like the power to the wiper comes in at 53a and then goes to the switch (purple/black wire?) which in turn slects the resistors to get power to the motor to set a speed. I think the second circuit is for the manually operated windshield washer and gets it's power directly from the fuse and then to the wiper motor.

What you might want to try is checking the voltages at wiper motor pins 53, 53b and 53e to see what happens at different switch positions.

Maybe Warren can shed some light as well.

correct typos and grammar

randywebb · 03-20-2006, 12:01 PM

Here is the switch diagram - The washer can't be it as it only has one 'speed' - any thoughts on what the diagram means?

randywebb · 03-20-2006, 12:03 PM

Here is the switch diagram - The washer can't be it as it only has one 'speed' - any thoughts on what the diagram means?

HarryD · 04:58 PM

Randy,

I am somewhat confused too but lets look carefully at the sketch.

The left hand switch has three optional positions and the right hand one has two optional positions. The washer switch has two functions, one to run the wahser pump and one to start/run the wipers. In position one, the wipers are started and in position two the washer motor is energized. That, in my mind explains the Arabic numbers.

As far as how the wiper switch (left hand side one) works, I am unsure because I am not sure what the symbols are. Perhaps a more legible diagram from the Shop manual might help.

If you look at the switch, you will note that position I connects #53 with 53a and an internal connection to 53b. Position II connects 53a AND 53e with 53. Position III connect 53 with 53a and the little box inside the switch. All we need to know now is what the boxes are.

HarryD · 03-20-2006, 05:36 PM

Moving on... At the wiper motor, the round thing on the right is a cam to park the wipers and it provides power to the motor until the cam opens the switch (parked postion).

While running, the power is supplied (somehow) via 53, 53b and 53e to the motor. the square boxes you see are resistors to control the current and hence the motor speed.

How does it all work? Hey Heck I am ChE not an EE.

randywebb · 03-20-2006, 08:05 PM

"and one to start/run the wipers."

- I wasn't thinking about that -- it makes perfect sense tho. Thx!

HarryD · 03-20-2006, 10:34 PM

Quote:

Originally posted by randywebb
"and one to start/run the wipers."

- I wasn't thinking about that -- it makes perfect sense tho. Thx!

Great. Now maybe we can figure out how those crazy Germans got the three speeds to work!