Help w/wiring an accessory (led plate)

[tysamigo]

I was hoping someone could shoot me some advice. I have an LED License Plate Holder that scrolls words. It's something like this:

http://www.kleargear.com/1904.html?utm_medium=shoppingengine&utm_source=googlebase&cvsfa=4371&cvsfe=2&cvsfhu=31393034

It's not exactly the same, but close enough.


It has 3 wires:
Black = Ground
Red = +12VDC
Blue = per the manual you have one of 2 choices:
(1) SPST Toggle to +12VDC. This will operate the plate only when the switch is on
(2) Tie the RED and BLUE together and instead of running to +12VDC, run it to brake lights. This will operate the led plate when the brake lights are on.


I wanted to do a 3rd option but don't know quite how to wire it. I feel like it's a simple solution, but I just can't figure it out...

I wanted to have a toggle switch (I think SPST, not sure though) so that when it's switched to position 1, the led plate will illuminate. When it's switched to position 2 it will ONLY illuminate when the brake lights are depressed. This way if I see a cop, I can switch it to "legal" so that it's only on with the brakes.

How do I do this, and what kind of switch would I need?

[etlsport]

You can do this pretty easily with a 3 position rocker switch but use it backwards.

Normally you would run power into the input then one output from position 1 and one from position 2. Instead run power from your brake light into the position 1 output and constant power into position 2 output. Then connect the input of the switch to the blue wire. That way when your switch is in position 1 your brake lights and blue wire are connected. When the switch is in position 2 your constant power and blue wire are connected.

Your red and black wires would be connected normally to 12v and ground

[tom4bren]

Eric is right on.

Hopefully the attached diagram helps.