I'm working with a car radio face plate. You can apply voltage in either direction and have all the button incandescent bulbs turn on.

Behind the LCD panel there are two bulbs on their own circuit. Again, you can apply 12+ or negative to either lead and have the bulbs come on.

I am trying to put two LEDs with their own resistors in place of the LCD bulbs.

Problem is, I don't know which side the factory radio provides + and - to and there's no way for me to find out.

I can't seem to find the component that I need in order for the LED/resistor to power on regardless of which direction the + /- is coming into it.

I've been looking at rectifiers and diode bridges, but that doesn't seem to be the right thing.

 

I just answered this in the Chat section. Double posting is a no-no.
Mods notified. They will fix the mistake.

 

Hello,

You already have a thread for this:
Non polar LED wiring components

Bertus