Tracing an Open with an Ammeter

If the technician now places an ammeter in the circuit, the total current would be indicated as 2 amperes as show in Figure 174 instead of the calculated 3 amperes. Since 1 ampere of current should be flowing through each branch, it is obvious that one branch is open. If the ammeter is then connected into the branches, one after another, the open branch will eventually be located by a zero ammeter reading.