So I assume you are using the simple method of a light
on a wire to test if you have power. And this light
is an LED, or you replaced with with an LED.
Do your self a favor and pick up one of these.
harbor freight has them often on sale for 4.99 or even free. You can also pick them up on Amazon. You can read the true voltage reading of the battery
, if you connect the leads backwards it just reads the voltage as negative (but that does not matter). You can check current draw (put the leads in line with the circuit). Everyone should have one in their tool kit.