Ever gazed at a Halloween skeleton that eerily turns its head or a mannequin that waves at passersby and thought, “How did they do that?” The secret might be simpler than you think – a repurposed wiper motor from a car!
These little powerhouses are a favorite among DIY prop makers, offering a cost-effective and reliable way to bring movement to props. But how does one go from an old car part to a dynamic display?
That’s exactly what we’re diving into today. We’ll unravel the mysteries of your wiper motor’s power requirements, decode the color-coded world of wiper motor wires, and delve into the best practices to ensure your motorized prop operates smoothly and safely. Whether you’re a seasoned tinkerer or a newbie looking for a weekend project, by the end of this wiper motor wiring tutorial, you’ll be equipped with the knowledge to animate your imagination. So, let’s roll up our sleeves and start our journey into how to wire an automotive wiper motor to create dynamic moving animatronics and props!
In This Wiper Motor Wiring Tutorial:
Accessing the Wiper Motor Wires
All wiper motors pretty much function the same way and will work just fine for your motorized prop. But they do come in a variety of designs, some of which make wiring easier to do than others. With regard to wiring, you can group wiper motors into two main categories: those with an external wiring harness and those where all wires are internal.
Wiper Motors with an External Wiring Harness
These wiper motors have between three to five wires coming out of the body and terminating in either a male or female connector. My wiper motor has five wires and they all go into a single female connector. Another feature I like is the fact that the wiring harness coming out of my wiper motor is long so I have plenty of length to work with.
Some wiper motors have their wires split and go into two separate connectors. Either way, having the wires on the outside of the wiper motor body makes it easy to make connections using wire nuts or by soldering.
Looking inside the connector I can see the metal contacts corresponding to each wire coming in from the other side. In order to connect to these wires, I can either buy a matching male connector or simply cut off my female connector, leaving the wires free to work with.
Wiper Motors without External Wires
Some wiper motors appear to have no wires on the outside whatsoever. This is because all the wiring is internal. The only way to access them is through one or more male connectors attached to the body of the wiper motor itself. Inside the male connector, you’ll often see metal tabs or pins. In order to make your connections, you can either buy the matching female connector(s) or simply make your own terminal connectors.
Attaching female terminal connectors to wires is extremely easy and only requires some wire and a crimping tool. I recommend getting a electrical connectors kit because it will have a variety of common sizes that will be useful for future projects. Once you build your first motorized prop, I guarantee it won’t be your last!
Wiper Motor power Requirements
A wiper motor on its own is not going to be moving much of anything without power. To get your wiper motor working correctly you’ll need to provide it with the right operating voltage and supply enough current to get the torque you need for your motorized project.
Wiper Motor Operating Voltage
Since wiper motors are automotive parts, figuring out what operating voltage you need is pretty straight forward. When installed in a car, a wiper motor is run by the car’s 12-volt battery so you know that the power supply you choose has to provide 12 volts.
The speed of many DC motors, including wiper motors, can be influenced by the voltage supplied. A higher voltage often results in a faster rotation, while a lower voltage results in slower rotation. While wiper motors can tolerate some deviation, excessively high voltages for prolonged periods of time can damage the motor or reduce its lifespan so it’s best practice to stick with the wiper motor’s rated operating voltage, which for the most part is 12 volts.
Wiper Motor Current Draw
Figuring out how much current your wiper motor will need is not as straight forward. The amount of current flowing through a motor is directly proportional to the torque it produces. When a wiper motor encounters resistance (like having to move a heavy part of your prop), it draws more current to produce the additional torque necessary to make the movement happen.
In order to find out how much current your motor needs we could go through a series of calculations based on a sample project, but I’ll save that for another tutorial. Let’s just cut to the chase this time because if you’re reading this, I assume you have a great creature you’re trying to get ready for the season!
For the vast majority of your motorized props, a 12V power supply with a minimum of a 5A rating will work really well. Unlike voltage, supplying more current than your wiper motor needs won’t hurt it. Having more amps will allow your prop to move heavier loads. But like with everything else, there is a limit to the load your wiper motor can rotate, no matter how many amps you give it. This is known as the stall torque, or the load that causes the output rotational speed of a motor to become zero.
It’s not a good idea to have your wiper motor operating very near the stall torque rating for lengthy periods of time because the motor will run hotter and this will reduce its lifespan. If you’re concerned about the weight you’re trying to move, you can find the stall torque for your wiper motor online by looking up the datasheet for the manufacturer and model. For most props made with a PVC or wooden frame, you usually don’t have to worry much about the stall torque because wiper motors are plenty powerful for just about all your motorized prop needs.
Best Power Supply for a Wiper Motor
A 12V 5A power adapter is all you’ll need to power the wiper motor that will animate the majority of your motorized props. For good measure, it doesn’t hurt to add a few amps so sometimes I opt for a 12V 8A power adapter. These power adapters will all have a male barrel jack plug.
Some power adapters come with a female jack adapter accessory that you can use to connect your wiper motor to. I always prefer this method to having to cut off the male end of the power adapter in order to wire it to the wiper motor. Keeping your power adapter intact makes it easy to unplug it from your motorized prop when the season is over and use it for something else.
How to Wire a Wiper Motor for Motorized Props
If you have an external wiring harness with a plastic connector on the end, you may decide to cut it off at this point and make connections with wire nuts as we figure out which wire does what. When I buy any component, I try to keep everything intact until I confirm it works. With my female connector, it turns out that I was able to use breadboard Dupont-style jumper wires to make temporary connections. Once I figure everything out, then I’ll cut the female connector off.
If all you have access to on your wiper motor is a male connector with metal tabs or pins inside, you can make some quick connections with alligator clips for testing purposes. Otherwise, you’ll have to make a few wires with female connectors at the ends.
Identify the Wiper Motor Wires
I usually buy the five-wire wiper motors so I have the option of using it at either the low speed or high speed setting. Figuring out which wire does what takes a little trial and error, and unfortunately, there doesn’t seem to be a consistent wire color scheme that manufacturers stick to. This means that the colors I identify on my wiper motor may not do the same thing on yours. You may even have slightly different colors than me, especially if your wiper motor only has three or four wires. Never the less, there are some rules of thumb to help you get started.
Finding the Wiper Motor’s Ground Wire
Identifying the wiper motor’s ground wire is a great first place to start. By convention, the ground wire is almost always black, but keep in mind that it might be a different color on your wiper motor. One sure fire way to tell, is that the ground wire will also be bolted or physically connected to the body of the wiper motor. Other times, the ground wire will come out of a different part of the wiper motor than the other wires.
If all you have is a male connector with metal spades inside, you’ll have to use a process of elimination by just picking one to start with.
I did all my testing with breadboard jumper wires but you’ll most likely be doing them with regular wires. Insert the wire you suspect is ground into the negative screw terminal of the female jack connector and tighten it securely. Then connect the other end of that wire to the ground wire of the wiper motor.
Now there’s only one connection left to make, but which of the remaining wiper motor wires should be connected to the positive screw terminal of the female jack? Let’s find out!
Figuring Out the Other Wiper Motor Wires
Take each of the remaining wiper motor wires and insert them one by one into the positive screw terminal of the female jack connector and see what happens. Below are my results:
- High Speed Wire: Yellow
- Low Speed Wire: Green
- Park Feature: By process of elimination, my red and white wires are for the park feature. When I plugged either of them into the positive screw terminal of the female jack, nothing happened.
We’ll get into more details about the park feature a little later, but at this point if the high or low setting works for your prop, you can proceed with wiring up your wiper motor using more secure connections like wire nuts, inline wire connectors or soldering.
Changing the Direction of Rotation
If you need the arm to rotate in the opposite direction, it’s as easy as reversing the wires!
When I connected the wiper motor’s ground wire to the negative screw terminal of the female jack adapter and either the low or high speed wire to the positive screw terminal, the arm of my wiper motor turned clockwise.
To go in the opposite direction, or counter-clockwise, connect the wiper motor’s ground wire to the positive screw terminal of the female jack adapter and the speed wire of choice into the negative screw terminal.
Motor Speed Controllers
You might find that only having two motor speeds to choose from is quite limiting for the movement you’re trying to create. You could try slowing down the rotation by using a power adapter with less volts. This will take some trial and error, and not all wiper motors will work with anything less than 12 volts.
The best way to control the speed of your wiper motor is with a motor speed controller. You simply turn a knob to precisely adjust to the speed you want. The most common type is a Pulse Width Modulation (PWM) controller. PWM controllers work by varying the width of the pulse of power supplied to the motor. By rapidly switching the power on and off and adjusting the duration of the “on” state, PWM controllers effectively control the average power delivered to the motor.
Most motor speed controllers will have screw terminals for you to easily connect a power supply and your motor wires. On the opposite side is a knob that you can turn to adjust the speed of rotation on your wiper motor.
How to Wire a Wiper Motor to a Speed Controller
In order to use a motor speed controller with your wiper motor, just insert the positive (+) and negative (-) wires from the female jack adapter into the corresponding screw terminals of the motor controller and tighten them down. Then take the ground wire from the wiper motor and connect it to the Motor- screw terminal of the controller. Finally, take the high or low speed wire and insert it into the Motor+ of the controller. I usually pick the high speed wire for this because it gives you a wider range of speeds.
Double check that all your connections are secure by giving them a gentle tug and plug in the power adapter. As you turn the knob, the motor speed will change accordingly, slowing to a complete stop on one end and accelerating to its full speed on the another.
Wiper Motor Parking Feature
Whenever you turn off the power to your wiper motor, your prop will stop moving immediately and be stuck in whatever position it happens to be in. This can be a bit awkward if you want your prop to have a specific starting or resting position when the motor is off.
When used in a car, a wiper motor’s parking feature is a built-in mechanism designed to ensure that the windshield wipers always return to their “park” position (usually at the bottom of the windshield) after they are turned off. This way, the wipers don’t just stop abruptly where they’re at and potentially obstruct the driver’s view.
If you’re designing a prop that needs to start and stop in a specific position every time, using the parking feature can help you achieve this. For instance, a peeping zombie can rise up from behind a tombstone and lower back down to its starting position for the next round of scares.
Incorporating the parking feature of a wiper motor can be done manually with a SPDT (single pole double throw) on/on switch, but is much easier to do with either a 555 IC timer and 12V relay, a programmable dc motor controller or a microcontroller like an Arduino.
How to Identify Your Wiper Motor’s Park Wire
Remember the red and white wire I had left over that didn’t seem to do anything? It’s time to assign them some jobs!
When you turn you wipers off in a car, the motor still needs power to “park” the wipers in place. So one of these wires is normally hooked up to an ignition source in the car. By convention, I’m guessing the red wire is the constant power. Therefore the white wire must be to activate the “park” action.
In order to test this, bust out your multimeter and set it to continuity mode. Don’t know how to use a multimeter? Check out my multimeter tutorial to get up and running with perhaps one of the most valuable tools to get you out of all kinds of electronic trouble.
Power on the wiper motor using whatever speed wire. Touch one probe to the wire you suspect is the park wire (white in my case) and the other probe to the metal housing of the wiper motor. You should hear a beep once per revolution. Pay attention to the position of the arm when you hear the beep. You’ll notice it happens at the same spot every time.
If you don’t hear a beep, then try another wire.
How to Wire Your Wiper Motor to Use the Park Feature
To put the park feature to use, you need to connect one of your speed wires (high or low) to your park wire. You can see the park feature in action with a single pole double throw (SPDT) on/on or on/off/on switch. Here’s how you would wire it up to an on/on switch:
When the switch is in the “RUN” position, your wiper motor will operate normally. When switched to “PARK” it will continue to rotate until the arm reaches the park position. Then it will stop until you flip the switch again.
Since I only had an on/off/on switch, here’s how I wired it (for testing):
By throwing the switch forward, the yellow (high speed) wire will be connected to the red (power) wire and the motor will run. In the middle position, the motor stops because the yellow speed wire isn’t connected to power anymore. Throwing the switch backwards will connect the yellow wire with the white one (park) and cause the arm to move again until it reaches its parked position.
The park feature can be very useful for creating starting and stopping points for your animations. But it’s not very realistic to have someone flipping a switch all night long to operate your prop manually, so the best way to use the park feature is with either a button-programmable motor controller or by writing a program for microcontrollers like the Arduino. We’ll cover more advanced ways to control your wiper motor’s speed, direction and park in the next motorized props tutorial.
Wiring Wiper Motors for Props Like a Pro
Adding movement to your Halloween decorations, attractions, or special projects by wiring wiper motors can greatly enhance the overall effect and leave a lasting impression on your audience. While it may seem challenging at first, with the right tools, a clear understanding of power requirements, and a system for identifying wires, you can successfully bring your props to life. Whether it’s a hauntingly realistic Halloween scene, an interactive attraction, or a unique project, motorizing props with wiper motors are sure to captivate your audience and elevate your creative vision to new heights.
