Volt /Ammeter at odds ??

My volt meter and ammeter disagree. My volt meter reads about 14 V with a little accelerator. My ammeter reads slight discharge always a little more with lights or any electrical device on. Whats up, and please dumb it down. I know the difference between amps and volts, just don't understand why they read opposites.

also check the studs on the back of the ammeter to make sure that they and the connections are good an tight...

I speak german ---> gudentight.... :D