# Wiper motor issue



## DarkOne (Oct 16, 2012)

Hello Everyone!

I've tried looking for an answer but have had no luck. I'm trying to use the park feature on my wiper motor like in this video:

https://www.youtube.com/watch?v=1Ww5-pmiokchttp://

I am powering it with a 30A 12VDC power supply, ran through a PWM controller like this









The motor is from a Jeep liberty and has the exact color wires like in the video. I hooked up my multimeter and it seems that the blue and green wires are indeed hooked to a switch. So, when I put power to the green wire to get it to park, it shorts out like it should but blows the fuse on the PWM controller. After the first blown fuse, I had the foresight to buy 100 of them from China, but I figured it happened because the motor rolled over on top of some wire disconnects and shorted. 
But now I have it mounted securely and I've blown 2 or 3 more fuses.

Has anyone used the park feature with this kind of PWM controller? If I can't get it to work, I'll hook up a separate limit switch and use an arduino to control the on off but would rather not have to for simplicity's sake. I appreciate your help.


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## David_AVD (Nov 9, 2012)

The way you should have wired it was + and - from the power supply feeding the motor speed controller board.

Use the + and - motor output from the board to feed to wiper motor as if it was being hooked up to the power supply directly.

Do not run any wires directly from the power supply to the motor.

Have you tried using the parking feature with just the power supply ? Did that work ?


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## DarkOne (Oct 16, 2012)

Thanks for the response. I had everything hooked up at the PWM and the power supply was only attached to the plus and minus input on the controller. I'll try it tomorrow with just the power supply again, but I think that popped a breaker on the power supply as well. Maybe there's something wrong with the motor?


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## David_AVD (Nov 9, 2012)

Either that or the wiring isn't quite as you thought it is.


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## DarkOne (Oct 16, 2012)

Well, when I hook it up without the PWM, my power supply protects itself by shutting down momentarily. I planned on using this power supply to supply more than one prop, so I can't have the park feature stopping everything.
I also figured out that I'll need to use an arduino to control the switching of the wiper motor to use the park feature anyway, so I'll just add an external switch to tell the arduino when the motor arm is where I want it to shut off.

Thanks for trying to figure this out with me. I'll take it from here.

Happy Halloween!


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## corey872 (Jan 10, 2010)

That is a good tutorial, worthy of a bookmark / sticky.

Though you might want to re-watch it. You should never be "applying power to the green wire to get the motor to park".

You should apply power to the red or brown wire (depending if you want high or low speed) to move the motor out of the park position. Once out of the park position, power continues to the motor through your switch.

If you turn that switch 'off', (ie disconnect red or brown wire) you should instantly make contact with the blue wire so power continues to flow in the blue wire, out the green, through the other contact of your switch and through the motor. Once the motor reaches park, it breaks the power contact on the blue wire and makes the contact to ground on the green / power wires to 'brake' the motor in the park position.

It's a slightly advanced 'interlocking' mechanism, but the bottom line is - with the motor in park, the green wire is grounded, so sounds like it's behaving as it should - including blowing your fuse.


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## David_AVD (Nov 9, 2012)

Agreed. There is some mis-wiring that is causing the park feature to not work correctly.


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## DarkOne (Oct 16, 2012)

You're absolutely right! I shouldn't have been applying power to the green wire! DUH, I mixed it up in my head. Having said that, when I did apply power to red, switch over so red and green are connected , I got it to park precisely once. The power supply whistled a bit, I disconnected the green and red, the power supply continued to whistle for a couple seconds then stopped. It didn't blow a fuse or breaker, but I cannot get it to park again.
(And no blown fuse on the PWM controller)

Thanks for catching my mistake!


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## corey872 (Jan 10, 2010)

Guess it will depend a bit on which red of the 'green and red' you're talking about. You have 'red' from the power supply. We should probably call that "+" for clarity. Then you have red on the motor - which we could still call "red" or 'motor red'.

So given that convention, you would ground the motor case (always), and hook blue to "+" always. Then hook + to red and the motor should start turning. (green totally unconnected at this point)

If you want to park the motor, you need to break the + and red connection, and immediately make the red and green connection. This will brake the motor and stop it in the park position the next time around. 

You can do this by hand, but you need to be fairly fast at it. If you use a switch, you may need a somewhat specialized 'break before make' switch - meaning the contact of one side breaks before the other side makes. (The converse switch - make before break - would create a momentary short on the circuit in certain conditions)

Lastly, if you don't break the + / red and make the red / green connections in a solid, timely manner, the motor may not properly stop in the park position. If it overshoots a bit, would have a small possibility to get caught between the parked and running state...that might lead to the whistle you heard.

It would also be important to know what 'cannot get it to park again' means. ...stops as soon as you remove + to red power? ...continues to run always once you remove + / red and doesn't stop at the park position? ...overshoots park and finally stops?


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