Don Tuite wrote in
:

Are we talking about a Piper?

If so, the "ammeter" is a "load" meter that reads current. It shows
how much current stuff in the airplane is sucking. If you have the
pitot and landing lights on, it should show a pretty heavy load. Most
of the time, it doesn't indicate much, because radios and stuff don't
present a very big load.

Don,

We are talking about a Sundowner, and it does exactly what you describe
when I put on the landing light and pitot heat.

Though landing light seems to pull a heck of a load for a simple light, but
been told that's normal.

Pitot heat doesn't pull as much load.

Thanks all for explaining the ammeter!

Allen