The ammeter is part of the circuit, except for '76 which uses a shunt wire.
Both studs should be at system voltage. No measureable resistance should be present in the gage. It acts like another section of wire unless the studs get loose.
I took out the ammeter and extended the ammeter wires which are now going to an external voltgauge. so now the voltgauge is not flowing current but stopping it to read it. so my fuse block is not receiving power