Wiper Function

No, they should be two speed. But on most of them the speeds are “slow” and “slow”

They should park themselves. This requires the foot washer switch to be both present and working properly. You can jumper two wires at the foot switch connector to see if that’s the problem? I think you connect the two blue-white wires: if you do that and it parks, then the foot switch is bad.

Lemme check tomorrow to confirm how I jumpered mine.

Mine were like you describe when I got my car. I found problems with the toggle switch, the foot pump and wiring on the motor. The electrical connections on the foot pump are involved in high operation and the park function, because when you press the foot switch (to operate the screen wash) it should trigger fast wipe and when you release, the wipers should park - so this may be a good place to start your checks. Replacement toggle switches, foot pumps and motors are available.

Incredibly helpful information, thank you all for replying! The foot washer switch was not even present on my car, so I dug through the random parts box that came with my car and found it. Connected it to the wiring plug under the dash, and that fixed the high speed problem. However, the wipers still won't park. I also see that I only have 3 wires connected to my wiper switch: a blue, blue/black, and a white/black. Interesting that @quadrifolio 's diagram shows wiring of a different color. Is the missing 4th wire on my car what sends the 'park' signal?

It looks like this thread has the wiring for the three-wire switch:

RenaissanceMan said:

Interesting that @quadrifolio 's diagram shows wiring of a different color. Is the missing 4th wire on my car what sends the 'park' signal?

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the blue-black wire is the one in my diagram thats always powered and is for the parking signal

Wait a minute, wipers can automatically return to the home position? Doesn’t happen on my GT Junior either. Should it?


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General Boy said:

Wait a minute, wipers can automatically return to the home position? Doesn’t happen on my GT Junior either. Should it?


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Click to expand...

I would say yes, if the toggle switch, footswitch, motor (3 or 4 wire) and wiring is correct. Full function is off, slow wipe, fast wipe, fast wipe when foot switch is pressed, to operate screen wash pump bulb. If wipers are switch-off, they should park at the base of the screen, if the foot switch is released, the wipers should park at the base of the screen - or go back to slow/fast wipe if the toggle switch is set to slow/fast. I think some early models had single speed. If they don't park, I think it means that the "always hot" feed to the motor is not getting through.

Yes.
That ‘always hot’ wire supplies continuous power to the motor until it is interrupted by a slot/gap in the rotating contact plate in the motor housing itself. When this gap in the rotating plate arrives at the copper contact supplied by that wire, contact ceases, power stops, motor stops, wipers are parked.
If your wipers park, but park in the wrong place, there’s an added trick involving ‘clocking’ the small connecting arm at the motor drive to ensure the entire wiper mechanism is at full-stretch when the motor is in park position. That is, you can’t change where the motor stops, but you can change the orientation or stop-point of the mechanism, and, following that, also the position of the wipers to ensure everything stops where it should.
Even the earliest, single-speed 105 systems had wiper-park facility.

Here is my understanding of the circuit.
The Blue/Black is always at 12V and it feeds the micro switch in the wiper motor which is always closed except in the park position. The Blue/white wire is connected to the other side of the micro switch. If you connect a volt meter to the Blue/white and GND while the motor is running you will see 12v except for a brief interval when the wipers are in the park position.
IF THE SWITCH IS IN THE OFF POSITION the blue/wite is connected through the switch to the blue wire which is the slow speed connection to the motor. So with the switch OFF it is not supplying 12V directly to the gray (fast) or blue (Slow) but it is supplying the blue slow indirectly through the micro switch and the blue white wire.
This is the way it works with the 8 pin rocker switch.
It is totally different with the 4 or 5 pin toggle switch.

Excellent, looks like I have week end project!


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Ranz said:

Yes.
That ‘always hot’ wire supplies continuous power to the motor until it is interrupted by a slot/gap in the rotating contact plate in the motor housing itself. When this gap in the rotating plate arrives at the copper contact supplied by that wire, contact ceases, power stops, motor stops, wipers are parked.
If your wipers park, but park in the wrong place, there’s an added trick involving ‘clocking’ the small connecting arm at the motor drive to ensure the entire wiper mechanism is at full-stretch when the motor is in park position. That is, you can’t change where the motor stops, but you can change the orientation or stop-point of the mechanism, and, following that, also the position of the wipers to ensure everything stops where it should.
Even the earliest, single-speed 105 systems had wiper-park facility.

Click to expand...

sent mine to a local gen/starter shop and had it rebuilt,

Ok so I went through the wiring and here is what I found... There are 4 wires coming from the wiper motor but only 3 of them are being used: A blue, a blue/black, and a gray. (the gray changes to a white/black at the connector). These are the same 3 wire colors at the wiper switch. The 4th wire coming from the wiper motor is a white/blue but again this is not connected anywhere. The connector routes to the foot pump and the connections coming directly from the wiper switch are summed there also. Power is running full time to the blue/black wire at the terminal at the wiper switch and also at the blue/black wire at the foot pump wire connector. So I'm assuming the wiring is all correct. If the wiper switch is working correctly, and if the foot pump switch is powering the wipers properly at high speed, but the wipers never park, is it safe to say the foot pump switch is bad? Also is there a more direct way to test the foot pump switch?

Yeah, unplug the foot switch and jumper between the two white/black wires. If the wipers park then the foot switch is bad.

White/black to white/black is NC on the foot switch and blue to blue/black is NO. Connecting white/black to white/black triggers the park, and connecting blue to blue/black triggers fast wipe (all assuming I'm reading the post I linked to above correctly...my car has the four-wire setup).

Gubi said:

Yeah, unplug the foot switch and jumper between the two white/black wires. If the wipers park then the foot switch is bad.

White/black to white/black is NC on the foot switch and blue to blue/black is NO. Connecting white/black to white/black triggers the park, and connecting blue to blue/black triggers fast wipe (all assuming I'm reading the post I linked to above correctly...my car has the four-wire setup).

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Thx for the reply. When I jumper the 2 white/black wires nothing happens.

Then it's possible that the electrical contact in the wiper motor that manages the park function is broken. I know this is accessible on the Lucas motors (I fixed this same problem on my Giulia) but I don't know about the Bosch motors, sorry. Hopefully someone else can help.

Does anyone know what the purpose of the single gray wire is referenced in @quadrifolio 's diagram and the 4 wire Alfa diagrams?

Gray should be fast wipe. When you push the foot switch, gray connects to +12 blue to trigger the wipe. Then when you release the switch blue-white connects to blue-white to park.