M2/M3 BFV: BULL POWER DIST SYSTEM - OD1606 - LESSON 2/TASK 1
broken or loose wires, closed or short circuits and burned-out lamps.
First, set the RANGE switch to RX 1, unless there is a transistor in
If a transistor is in the circuit, use the RX100
setting. Plug the black lead into the -DC AC jack and the red lead
into the upper left OHMS jack (figure 38 on the following page). Now
set the FUNCTION switch to the OHMS position.
Now touch the black
lead to one end of the circuit and the red lead to the other end. If
the needle swings to the extreme right, the circuit could be either
closed but good or closed but shorted depending on the reason for the
test. When testing solid state circuits, if the needle doesn't move,
try switching the probes at the point of contact.
If the needle
still does not move, the circuit is open.
If the needle flickers,
this indicates a loose connection.
(b) Resistance Tests. Resistance tests are used to measure the
resistance of coils and resistors.
battery voltage is connected to the circuit to be
Use the meter to see if any voltage is
present, or disconnect the battery ground cable.
This will prevent possible burnout of the meter.
AC jack and the red lead into the upper left OHMS jack.
FUNCTION switch to the OHMS position.
If the approximate ohms rating of the circuit being tested is known,
set the RANGE switch to that RX value. If the rating is not known,
set the RANGE switch to RX10000.
When testing the resistance of
transistor circuits, use the RX100 range setting only.
the meter's power source to only