Electronics guru's I need help

[IMR-Merlin]

Guys I am in the process of integrating my factory wiper motor to the painless wiring harness. Does anyone know what makes the wiper motor return to the "home'" or "down" position after you turn the switch off? I can get the high and low to work and assuming the intermittent is the other wire. Do you have to use the intermittent relay as part of the system for the wipers to return home?

thanks for any advice.

[WinRice]

It's been awhile, but on my 86 wiper motor there is a red/white wire that provides +12V to the park switch inside the motor directly from a fuse (fuse 7, box 1). In other words, the motor has to have an unswitched +12V to it that provides the power to park the wipers when the speed switch is turned off.

[IMR-Merlin]

I am running 12v+ to the red/white wire terminal 53a (i think) and figured that would park them...

[WinRice]

Now you made me pull out my wiring diragram....

53a has the red/white constant +12V, but the other side of the park switch goes to 53e which goes straight to 31b on the intermittent control unit. It looks like they use that for the loop to control the motor.

[WinRice]

BTW it looks like the int. control unit is also used to cycle the wipers a few times before they park when you pull the washer lever.

[WinRice]

Looks like the blue wire off 53 on the int. control unit goes through the wiper and washer switches (53e on the switch) when they both are in the off position to the low speed on the motor, so that looks like the power connection used for parking.

To bypass the int. control unit it looks like you need constant +12V at the red/white 53a on the motor, then connect blue/white 53e on the motor to the blue 53e on the switch.

I bet if you pulled up an older wiring diagram without int. it's probably wired this way.

[IMR-Merlin]

I am trying to limit the wiring and dont need the intermittent, so I am trying to bypass it. I will see if I have any older schematics. I am working off the 84-up Bentley.

[unclebilly]

Iirc, you provide the motor with a hot wire and switch the ground. We are running a painless harness in the 911 chump car and it seems to me that this is what we had to do.

[IMR-Merlin]

Ok, I was laying in bed this morning and had a thought. On the bottom of the motor, I have 2 wires which I assume go to the park switch.

This car sat from 1994 till just yesterday with the wipers in the park position. I am wondering if the switch is stuck in the depressed position!

I have the motor and linkage in the car right now for a test fit. When I pull it out later, I should be able to have continuity between the white wire and blue wire on the switch in roughly 350-355 degrees of motion. When the switch gets depressed, it breaks continuity to the red/white wire (53a) and stops the motor.

That sound plausible?

[IMR-Merlin]

The possible culprit....

[IMR-Merlin]

Ok, figured it out.

Let me start this by saying I want to really back date this and make it as barebones as possible. It's a seasonal car so no washer and no intermittent wiper.

That being said I figured out how to park WITHOUT the intermittent relay!!

On the back side of the wiper motor you have the "parking switch" that has a white wire and a blue wire connected to it. What I failed to realize was there was also a ground.



When you pull the cover off you can get an idea of how it works.




When the motor travels through it's cycle it has about 355 degrees of contact with the white to blue wire and then it settles into the "park" position and then blue wire goes to ground. Effectively making a reversing polarity switch. I am guessing that this is used to get those 3 full sweeps of the wipers after you hit the windshield washer.

so as you can see, there are 3 contacts....




so, in the factory setting and all 3 contacts in place, the red/white wire goes to the blue wire and while the wiper is not parked you have 12v going through the switch to the white wire that goes to terminal 53e. When the motor hits the park position, the white wire goes to ground. So terminal 53e is now grounded.

So what I did to make this motor work the way I need it to was to cut the contact that goes to ground so that terminal 53e will ONLY be 12v+ for the cycle and NEVER go to ground.



I then built a jumper from terminal 53e to the black/violet (intermittent) wire in.




So during the sweep of the motor, no matter what switch is on (low or high) the black/violet wire gets ignition switched 12v+. So if you were turn the wipers off, they will still have 12v to return to home.


I will just have one "dead" position on my wiper switch which I will deal with.

As for the washer pull switch, I am using this for the horn (removable wheel).

[WinRice]

Nice and simple!

The factory used the convoluted wiring through the wiper switch so the park switch only operated when both the wiper and washer switch were in the off position. That way the park switch could use the low speed motor winding, but the low speed winding wouldn't get power if the wiper was in the middle or high range.

[IMR-Merlin]

ha, I just came on to post. I will need to run a simple relay to take power away from the Red/white wire when I have the switch on. If the red/white is connected, I only have one speed. Simple fix and if I wasn't using the "pull" position of my switch to activate the horn, I would probably gut the whole wiper system out of the donor car.

[IMR-Merlin]

Ok, so here is the final result of my day. I have decided to use all 3 positions of the factory wiper switch.

position 2 = wipers low

Position 3 = wipers high

intermittent position 1 = returns wipers to park

This way I can have all factory connections with no additional relays and I use all 3 positions of the wiper switch.

wiring is straight forward. 53a is now connected to the 12v out from the wiper switch to be energized with the position 1. So if I use the wipers, I just need to put the switch in position 1 (intermittent) until the wipers park, then I can leave it there or turn the wipers off.