My ’99 Miata didn’t include an integral garage door opener but there were aftermarket modification kits available that inspired me to add one, with a few modifications, of course! Here is the write up that I created back then:
Tom Madracki, of Yorba Linda Miata, has an interesting garage door opener modification on his website. His opener modification activates the garage door opener whenever the high-beam headlights are turned on.
I thought this was great except for the fact that I drive with my high-beams on a lot of the time. Tom’s modification would cause the opener to activate continuously when the high-beams were on – draining the opener battery in no time. I changed Tom’s idea to add a simple circuit that would pulse the opener for 1 second whenever the high-beams were first turned on.
Here are the parts I used:
- R1, R2 = 1/4W 100KΩ Resistor
- D1, D2 = 1N4001 General Purpose Diode
- C1 = 4.7uF @ 25V Aluminum Electrolytic Capacitor
- C2 = 10uF @ 25V Aluminum Electrolytic Capacitor
- C2 = 0.01uF Polyestor Capacitor
- U1 = NE555 Timer
- K1 = DPDT 12V Miniture Relay V23079-A1003-B301
All of these parts are available from DigiKey
+12V is connected to the red/yellow +12V supply line to the headlamp bulb. GND is connected to the white, switched ground wire for the high-beam element. OP1 and OP2 are the relay contacts. Connect these in parallel with the switch on your garage door opener.
Here is the finished board made with a cheapo Radio Shack PCB kit (board artwork PDF file should print 1:1 but check dimension), and protected with Plasti-Dip vinyl coating:
I modified my garage door opener with the addition of a 3/32″ phone jack so I could disconnect it from the car if needed:
Installation is pretty much the same as Tom’s write-up. Use two 3M “vampire taps” to connect the 12V and ground wires to the headlamp connector. Now, when you turn your bright lights on, the opener will be activated for 1 second and then shut off.