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

    Distinguished Member

    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

    Well-Known 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...