amp gauge drawing battery down?

Is it possible that the amp in our 190xt is drawing battery down. is it possible the gauge is shorted out inside checked it with a meter and that is what it seems like to me.anybody had this problem before.i unhooked the battery and put my meter in between the battery cable and the positive of the battery and unhook the key and light switch and the wire to the alternator.it still reads 12 volts of draw unhook power wire to the gauge then i have 4 volts of draw take the gauge right out of the dash not letting it touch a ground and i have 4 volts of draw sounds like to me the gauge is shorted out.any other ideas? thamks for any other info.

It is possible for the ammeter to short to ground. Normally its circuit is completely insulated from ground. A good check is to disconnect both leads and hook a test light between the battery lead and either ammeter post. If the light lights, its leaking to ground. If you do that test with a volt meter instead of a lamp it may so sensitive that the ordinary gathering of dirt will make the volt meter read full battery voltage though the leakage current may be only microamps because it can take only 50 microamps to move an analog meter to full scale (like a Simpson or Triplett).

Gerald J.

Over time, moisture in the air breaks down the original fibre insulators around the ammeters posts.Small growths called 'dendrites' form ,allowing current to pass to ground via the mounting hardware.When I rebuilt the '53 G electrical panel, I used brand new nylon 'shoulderd washers' from a newer ammeter, painted the steel mounting bracket at the same time to prevent rust from forming and added a itty,bitty amount of light oil to the threads of the ammeter studs.