Circuit help - scanning led - ground when off - Toyota Nation Forum : Toyota Car and Truck Forums

WhiteRabbit · 04-13-2007, 08:14 PM

The LED on my alarm pooped out. Trying to install a scanning led to replace it. How do I wire the thing, need to know what circuit grounds itself when the car is off and where to get a constant 12v power source.

***Silver Streak*** · 04-14-2007, 07:44 AM

Can't you use the original wiring for the LED? If you use a constant 12v power source, then won't the LED be on all the time? Or are there three wires, ground, constant and trigger? You can typically grab it from your stereo, as it needs a constant for memory.

***YESCA*** · 04-14-2007, 09:45 AM

^^^ Thats what I was thinking.

fox_prime · 04-14-2007, 10:46 AM

How did your LED blow out? To be on the safe side, hook it up in series with a resistor:

existing wiring circuit ----- +LED- ------ 330-ohm resistor ----- GND

WhiteRabbit · 04-14-2007, 04:38 PM

well i dont think the led blew out, i think a connection came loose

wasnt sure if i could use the same wiring for the led since the alarm sends diagnostic blinks, dont know how that would work with a scanning led

wanted to wire to a constant 12v and to a circuit that grounds when the car is off so that it only turns on when the car is off and turns off when the key is put in the ignition