Ignition tapping trouble, could really use some help!

[Phoenixcolt]

Sup guys, trying to install a speaker/amp upgrade to my dad's truck and running out of time, he is traveling back to ga tomorrow.

Everything is ready to go but the ignition wire we tapped into at the back of the stock headunit is not putting out enough voltage to turn on the amp we are using. It is putting out about .08 volts at the amp even tho it's at 2.5v at the back of the radio.

If i am going to need to tap into a different wire, where should I go? The fuse box is in the engine bay so we can get to a wire there, but which wire would be best to tap into? To assure it wasn't the amp, i jumped the power wire input to the remote wire input and the amp lit right up.

What should I do? I am so out of time...stressed.

[CK1991]

I would run a switched power off the head unit switched (ignition) power feed. I would then put it to a relay that is turned on by the antenna/ amp turn on lead.