I got a Vehicle Tracking Unit, The Connection required is Red - +12V Black - GND Green - Ignition.

I need to test the unit before putting it into the car. So to simulate the ignition procedure, what is to be done?

The unit comes on only after the CAR is put on said the guy who sold the equipment to us.

Should the Green be tied to Vcc (+12) ? Or Ground for the On State?

  • I think the "connection required" section of your question needs clarification. How many wires (and colors) does the unit have?
    – JPhi1618
    Oct 30 '15 at 12:16

Tie the ignition wire to +12V to simulate ignition on. Grounding the green wire will simulate ignition off.


When you turn the ignition key on in a car, it provides +12 volts to the ignition system and accessories, so I would expect the green wire should be connected to +12 volts (but the documentation of the device should clearly describe its requirements).


If you are just testing the equipment, do the following:

  • Open the hood of your car.
  • Attach the black wire to the ground (negative or earth) side of your battery .
  • Attach the red and green wire to the positive (+) side of the battery.

The unit should light up.

If everything looks to be working, install the unit as described in the instructions. The black wire is obviously attached to the ground (earth). The red wire should be an always on source of power. The green wire should go to a switched source. It's easiest to find the switched power source through the fuse box. Piggy back it off of one of the other switched fuses and you'll be golden.

  • I'm having a hard time with this -- why would green ever get connected to +12v? Green is the universal color for ground.
    – JPhi1618
    Oct 30 '15 at 12:13
  • @JPhi1618: Green is Safety Ground in North American AC power wiring, but can be used for other things in other applications. (Black is Hot in AC wiring, but usually Ground/Negative in DC applications.) Oct 30 '15 at 15:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.