Introduction: 12 Volt Deer and Critter Chaser Alarm

Learn how to make a device that will protect your gardens from critters such as rabbits and deer that love to eat your prized landscaping plants.

I call this Invention the Deer Chaser. It is a simple concept where you use a remote control to power a 12 volt horn with a 12 volt DC power supply.

Main components for this project can be purchased from Harbor Freight and Amazon.

In the last 20 years the deer population in my suburban community has exploded. With no predators it keeps growing. (no hunting allowed) During the first 12 years in our home I enjoyed growing a vegetable annually. About 8 years ago a few deer devoured our garden just before the vegetables started to pop. That was the last year of home grown vegetables in our yard. Now we are just trying to keep a beautiful yard with perennials.

This device allows you to chase the deer at a distance of 100 away. Just push a button and watch the deer run away.

Step 1: Parts - Materials - Tools

Not many items needed for this great little project. Relatively speaking an inexpensive gadget made with a handful of parts.

The main components you will need is a weatherproof box of some sort, 12 volt battery, 12 volt horn, and 12 volt remote relay. Below are links to where you can buy online are the main components. Besides these parts 16-18 awg. wire and connectors will get you up and running.

Amazon: 12 volt remote relays. $8.99

Amazon: 12 volt battery. Already had a couple laying around from motorized vehicles.

Harbor Freight: weatherproof ammo box. $2.99

Harbor Freight: 12 volt Ooga Horn $6.99


  • Wire cutters and Terminal Crimpers
  • Screwdriver
  • Drill
  • 3" Hole Cutter
  • 1/4" Drill Bit
  • Sharpie Marker

Step 2: Disassemble Horn

Before disassembling the horn I recommend making a mark for proper alignment of holes later when you need to reassemble. I used a Sharpie to make a mark aligned with the mounting bolt.

Remove the 6 screws with a screwdriver.

Note when you disassemble there is a diaphragm between motor and horn. Make note of proper placement for reassembly.Re

Step 3: Battery and Horn Placement

This step is dependent on the box you use. My ammo box allowed for nice firm fit of battery and horn motor. Check alignment and spacing of both components.

Step 4: Mark Horn Mounting Holes

Use a Sharpie to mark mounting holes on ammo box.

Step 5: Drill Mounting Holes

With a drill and 1/4 inch drill bit drill the mounting holes.

Step 6: Drill Sound Hole

Before drilling sound hole, use a straight edge to connect mounting holes to find center for drilling.

With drill and 3 inch hole cutter drill sound hole.

Step 7: Horn Connectors

With 16 or 18 awg wire, Make pigtail connectors to be connected to + and - of horn. I had to bend my connectors to a 90 degree angle to fit in the box.

Step 8: Assemble and Install Horn

  1. Align and tape diaphragm to motor. Using the masking tape will ensure diaphragm does not shift and spin during install.
  2. Apply silicone to inside of horn. This will help ensure a weatherproof seal for outdoor use.
  3. Insert motor and diaphragm inside box and use 3 screws to mount motor to box.
  4. Use other 3 screws to mount horn to box and motor

Step 9: Wiring

Follow the wiring diagram to connect the Relay, Battery, and Horn.

Make the appropriate wire lengths and connections.

  1. Battery + will connect to Live Wire that connects to NC on relay.
  2. Battery + will also connect to Input + on Relay.
  3. Relay Comm will connect to Horn +
  4. Battery - will connect to Input - on Relay
  5. Battery - will also connect to - on Horn

Connections are made.

Step 10: Prep and Pack Relay Box

The relay that comes with a protective box to hold the relay. It is really of low quality and not truly designed for the relay. A little trimming with a utility knife will ensure nice fit if relay and wires.

Step 11: Pack It Up

Place wires and relay in box and close it up!

Your project is finished.

Step 12: Protect Your Plants Chase the Deer Away

Now the next time those pesky deer come by for a snack! Hit the button on the remote and scare them away. Perhaps now, we will get some blooms on the Black Eyed Susan flowers!

Another Instructable by the DiyWaterDog.

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