[thisquietplace]

I am currently wiring up the wiper motor on my harness. My Junior originally came with a 3-wire motor, but alfaholics sent me a 4-wire motor as a replacement a while back. Two of the three original switches on the left hand side of the 1750 dash are worn out, so my plan right now is to add some generic flat shaft toggle switches to replace all 3 (for now). I understand that the park function of the 4 wire motor is a bit difficult to get functioning on a generic off/on/on switch (with the original switch having a complex wiring setup), so my plan is to remove the dash board light switch (auto on with ignition from now on), and add two switches for the wipers. i am hoping to add an on/on switch as a power switch for the wipers (park connected to the "off" position of this on/on switch), and a separate switch for the two speeds. Will this work? what are the different color wires from the wiper motor exactly? ground/slow/fast/park? and which is which?

 

[alfaparticle]

The wires are 12v, fast, slow and park. The park wire is connected to the slow winding to park the blades. The ground is through the casing of the motor - there is no wire.
Blue/black - 12v
Grey - fast
Blue - slow
Blue/white - park

 

[thisquietplace]

The wires are 12v, fast, slow and park. The park wire is connected to the slow winding to park the blades. The ground is through the casing of the motor - there is no wire.
Blue/black - 12v
Grey - fast
Blue - slow
Blue/white - park

Thank you, should be able to figure things out from here!

 

[thisquietplace]

From what I understand, if 12v and fast or slow wire has power, the motor runs, and if 12v and park has power, it parks. If I use a single off/on/on-switch, and run an extra wire w/diode from each of the two "on"-connections to a relay, and connect the park-wire to 87a (on when off) on the relay, it will give me park with a single generic toggle switch?

 

[alfaparticle]

There is a micro-switch in the motor housing that is closed except in the park position. The 12v supply goes the the micro switch and the park wire goes to the other side of the switch, so the park wire is at 12 volts except when the wipers are in the park position. When this park wire is connected to the slow winding it powers the wiper motor until the blades are parked and then it switches off. If it were connected to the fast winding the momentum of the blades would keep the motor turning after the power was interrupted and the micro switch would close and the motor would not stop. The 8 connector switch used in S2 spiders only allows the park circuit to conduct when the slow and fast windings have no power.

 

[thisquietplace]

So if the switch wires are used to trigger the relay, the park wire is used as a power source for the relay, and the slow wire is connected to 87a (when off), it should work(?) Or maybe I am just over-thinking this.

I love relays, they are like if/else-commands from coding/programming

 

[alfaparticle]

If you had a 3 way switch and you connected 12 volts to the common, fast to position 1, slow to position 2 and a relay coil to position 3 and connected the contacts of the relay to the park wire and the slow wire, then you would replicate the 3 way switch in an S2 Spider.

 

[thisquietplace]

Perfect, thank you!

 

[HooliganSuper]

This is useful information, but boy do I need a schematic since I'm a visual learner. Can one of you draw us one?
Thanks in advance!
Bill Gillham

 

[alfaparticle]

This is useful information, but boy do I need a schematic since I'm a visual learner. Can one of you draw us one?

Do you want a diagram of the two switch solution?

 

[HooliganSuper]

Ed.
I'm begging here, so the choice is yours, but I do only have one hole in the dash, "the three way with relay" would fit in the dash of my Giulia Super ("Hooligan"). I think I have most of what I need here on the shelf.
I cant find a switch to get it all to work, I hadn't thought of the relay.
Thanks,
Bill Gillham

 

[alfaparticle]

Here is the circuit

This is a suitable switch http://www.digikey.com/product-detail/en/M2027SS1W03/360-3104-ND/4510687

Google SP3T toggle switch and you may find one that you like better.

 

[HooliganSuper]

Ed,
Thanks,
Do you have a number for the relay?
Bill Gillham

 

[alfaparticle]

Almost any 12V relay will work ..1 New 12V Bosch Style Automotive Relay 40A 30A SPDT with Socket and Harness | eBay

 

[thisquietplace]

Here is what I came up with for a on/off/on-switch (found a really nice one on ebay). I have not tried this to see how it functions yet, so please let me know if you have any input. The triangles are diodes.

 

[alfaparticle]

That looks like a good solution.

 

[Seliquella]

It's an old thread, but I found out that I have a 4 wire motor and a 3 wire wiring harness so I need to convert.
Looks like a smart solution, but whats the reason for the diodes in the last diagram?
And what's the difference with the first one?

 

[Seliquella]

Ok now the wife stoped vacuuming and the kids gone I got it.
It is a NC relay which is opened when slow or fast is activated. Diodes at the relay prevent connection between the slow and fast circuit. Diode in the slow is to prevent the relay keeping itself open in park mode.
When switch in off, the parkmode is active through the NC relay until fully parked.
What is the power of the motor so I can pick a proper diode, I can only find 1 and 3A in the automotive store, which might be a bit on the small side as it is fused by 8A (including brake lights 2x21W=3.5A)?
diode 1N5404 in steekzekeringbehuizing

 

[alfaparticle]

10A diodes are about 40 cents each on ebay and they seem to be widely used in the solar power business. I would use one of these 10A10 10 Amp 1000V 10A 1KV Axial Rectifier Diode 10 Pcs USA SELLER solar panel | eBay

 

[Seliquella]

Thanks for that, will check the electricians @work to see what we have laying around.
Will check te current for the motor by measuring, I linke the fuse blade style as the will fit my fuse box and are easy to reach if required.