custom car security system need help

Discussion in 'The Projects Forum' started by wet, Nov 5, 2013.

  1. wet

    Thread Starter New Member

    Nov 5, 2013
    I am making a trunk open detection alarm that will detect that the trunk of my car is opend by using a photocell to capture the light from the dome light of the trunk when it is opend.

    How would I go about soldering a circuit that would somehow activate a switch that would complete the circuit from a 12v line, triggering the alarm when the photocell is sending voltage.

    the green box is where i need assistance
    Last edited: Nov 5, 2013
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    Assuming this thread isn't closed,Why not just put a microswitch on the trunk body, so when the trunk is open it activates!
  3. Dr.killjoy

    Senior Member

    Apr 28, 2013
    Why don't you tap into the truck dome light wire and be done with it ...
    Also what if the bulbs burns out ??
  4. #12


    Nov 30, 2010
    There are better ways than to modify the car wiring, like a microswitch on the hinge or a mercury bulb or a rolling ball switch. Besides, modifying cars is not allowed at this site.
  5. strantor

    AAC Fanatic!

    Oct 3, 2010
    Maybe OP chose to do it this way because he/she knew the rules, and knew that the only way this discussion would be allowed to stay open is if there were no tampering with the car's electrical system; hence the detection of light - need not electrically interface with chassis wiring. Doubtful, I know, just playing devils advocate.
  6. adamclark


    Oct 4, 2013
    just get a mercury tilt switch and hook it to your dome light like you would any other switch...