MAINTENANCE OF M939 SERIES VEHICLES - OD1661 - LESSON 1/TASK 2
Step 2. In this step, SSG Heatherly tests alternator circuit 568
First, he disconnects the circuit 568 wire at
connects the meter positive lead to the circuit 568 wire and
negative lead to the vehicle chassis for a ground (figure 21).
Once the meter has been properly connected and all meter switches are
properly positioned, SSG Heatherly places the vehicle battery switch
to the ON position.
The meter should indicate a voltage reading,
which it does. Since the indicated voltage reading is not equal to
battery voltage SSG Heatherly will proceed with testing.
Now SSG Heatherly touches the positive meter lead to circuit
5, on the alternator terminal as shown in figure 22 (on the
At this point the meter should indicate