http://www.mymopar.com/index.php?pid=26

probably have to go here to chase it down.

if you have power on the black from the amp meter, then you should be good.

pretty much all your power taps off that at a single splice after the amp meter.

but the diagram shows a breaker attached to the amp meter too.
no idea where that goes to.

the fact you don't have ignition or headlights is weird.
and it could still be the amp meter. you are reading voltage not amps.
there may be 12 volts there, but maybe the amp meter won't pass enough amps to make anything work.