Help with wiring a red blinking LED

I purchased a red blinking fake alarm LED for my truck. I installed the LED in the blank switch plug to the right of the power converter button. Created a nice loom wrapped wiring harness that goes through the fire wall into the engine compartment.

The LED operated with two wires, a constant hot red wire, that is easy, going to attach the red wire to the battery. The second wire is black and must be connected to a switched power source. When the ignition is turned on the black wire gets power, turns to a floating ground, the LED stops blinking. Ignition / power off, the LED blinks.

This is where I'm puzzled. It seems the fuses both under the dash and under the hood are hot all the time. I've tried heated mirror, sunroof, heated seats and a few other fuses that I would think would be dead until the ignition is on. I've been using an "add-a-fuse", however, it seems all of the fuses are hot with the ignition off. I must be missing something here?

Has anyone else been successful with a similar project?

Any suggestions?

Thanks!

UPDATE

I cracked the code on finding the ignition controlled power source for my red blinking LED.

After 45 minutes of carefully testing each fuse under the dash I discovered that the two 15 amp fuses that control power outlet #1; on the dash under the AC controls and power outlet #2; which is located inside of the center console are control by the ignition.

I attached the red power wire from the LED to the battery with a 1 amp in-line fuse and the black wire from the LED was tapped into the 15 amp fuse for power outlet #1 using an add-a-fuse connection with a 1 amp fuse for the LED.

Ignition OFF, the LED blinks, ignition ON, LED is off / no blinking.

 

If it has 2 wires and one is attached to a continuous 12 volt supply and the other is attached to a switched 12 volt supply, how is that going to work? Having both conductors going to the positive side of 12 volts is not going to work. Unless the case of it is metal and grounded.

 

It's because the black wire will see enough of a load (difference between sides) in the "off" side of the ign wiring to allow a small amount of current (enough for a led) to flow. When the ign comes on, both sides equalize and no current flows - led goes off.