Ike,
Yes - this is a Doh! moment...
You must connect the two heavy wires that go to the (missing) ammeter together. (#24, I think). If you have a stout stud (say that 10 times fast
) on the voltmeter, connect
both wires to it. Be carefull! Short either wire and you may make some serious smoke (although the circuit breaker should present that).