L.E.D. Wiring Help?

Question

I would like to wire up a bi color 3 pole LED in my car to indicate when my compressor is running and when it isn't. I would like to use a DPST relay with this. Any help out there? I am a novice/amateur with some electrical knowledge.

Answer 1

I expect you want one color for off, and the other for on.

It will be necessary to find a conductor that has power when the compressor is running, and not when it is not. That conductor and negative could power the relay coil.
the "swinger" on the relay could be connected to a source of power whenever the ignition key is on. In the energizes state, one of the DPST contacts would power the "on" color. When deenergized, the other contact would power the "off" color. Both colors would be off when the engine is running.

You will need a resistance in the power lead to the relay swinger. I don't know what resistance it would take, but would try it with several thousand ohms.