not exactly.
it averages out to be 5 volts.
the pulse you see in the light is it opening and closing the circuit to make 5 volts on average.

so you would probably see 12 volts on a voltmeter.

what you need to do is tape 2 AA together so they are in series and then wire up the ends to your gauages and see if they work next, since you have it out.