[bestgenman]

The ammeter is driven from a current transformer (sometimes called a donut) that the main lead (there are two) passes through.  The output of the CT runs up to the front where it connects to the ammeter.  those leads are 16 gauge or maybe 14 gauge.  It is quite understandable that one of them could be severed or the meter or CT has failed.  Use Richard's check first and then look at the devices mentioned above.  You are welcome to call me 614-271-7488.  I'll be glad to offer any help.