Show All 8 Items
I am not the first to post a flashing LED for a fake car alarm. In my brief search I found one posted by artcfartc titled "Faux Car Alarm with Flashing LED." With that said, I have wanted to do this for a bit.
I recently purchased a old Chevy Pickup and wanted to add a flashing LED. I already had my Zombie friend in the truck, so I thought I would add him into the mix. The thought was to use the normally closed contact of a 12 volt relay to power a flashing red LED and the normally open contacts to illuminate the Zombie with a white or green LED. When the truck is off the red LED flashes and when the truck is running the Zombie glows bright green. The added bonus is the Zombie glows in the dark, so he is all charged up after a drive.
BE CAREFUL WHEN DRILLING HOLES AND WORKING WITH THE 12 VOLT POSITIVE BATTERY LEAD. ATTEMPT AT YOUR OWN RISK, THE AUTHOR IS NOT RESPONSIBLE FOR YOU BLOWING YOUR AIRBAG BY TAPPING INTO THE WRONG WIRE, OR DRILLING A HOLE IN YOUR ECU, OR SETTING YOUR CAR ON FIRE, ETC...
Step 1: Tools and Supplies
NOTE: Not all Items are in image
Step 2: Pick a location.
Make sure you can provide the needed power for the build. You will need a constant 12 Volt positive source, preferably already fused. If you run your source directly from the battery be sure to fuse it appropriately. You will also need switched 12 volt positive power from the ignition switch. This provides power only when the key is in the "on" position or the vehicle is running, it is often referred to as ACC for accessory. The last thing you will need is a chasis ground point, find a screw or bolt attached to something metal on the chasis.
In my application, I tapped into the 12 volt constant and the 12 volt switched from the stereo system and used a screw under the metal dash as a group point.
I used the climate control panel as a location for mounting the flashing LED. It is a visible place and there is easy access from behind the panel, I also did not want to drill into the metal dash.
The Zombie is conveniently located in the opposite corner. The LED to illuminate our undead friend is simply inserted into his body.
Step 3: Wiring diagram.
I used a terminal strip in a project box for a clean look and to be able to add things in the future. This build could be done without the box and the strip.
The Bosch relay pin format is:
Pins 85 and 86 go to the coil. I have ground going to pin 86 and switched ACC going to pin 85.
Pin 30 is wired to the constant fused 12 volt power.
Pin 87 is the Normally Open (NO) contact, this is wired to the green LED.
Pin 87a is the Normally Closed (NC) contact this is wired to the flashing red LED.
The Linrose flashing red LED comes with a resistor built in, it can be wired straight to 12 volts. The Linrose green LED I used had to be wired to a 680 ohm resistor to be used in the 12 volt circuit.
Step 4: Wire up the strip and relay.
Leave plenty of extra wire, depending on where you need to route it. Strip the wires and crimp the appropriate connectors for the relay. I did not have orange wire for the switched ACC wire so I used green. The terminal strip was trimmed to fit into the box and just sits in there. I used the heat shrink to cover all of the spade terminals on the relay to protect against shorts. Solder the wires to the LEDs and be sure to heat shrink the positive lead to prevent shorts.
Step 5: Drill your hole and install LEDs.
The flashing LED I used called for a 17/64 hole if using the panel clip. This may vary, be sure to check what size of hole is called for. Once the hole is drilled, install the panel clip from the front and the LED from the back of the panel and it should snap into place. Find a good place for your Zombie, and insert the green LED. Now terminate the wires to the power and ground sources. IT IS A GOOD IDEA TO DISCONNECT THE BATTERY WHEN WIRING TO A BATTERY POSITIVE CONNECTION.
Step 6: Test the system and clean it up.Once the wiring is complete test it out. The red LED should flash when the key is off, once the key is in the "ACC" or "ON" position the green LED should illuminate the Zombie and the flashing LED should be off. If it works, hide the wires with zip ties or tape and make it look nice and clean.