jcb JS300 Service Manual page 433

Measuring Continuity
1 Make sure there is no power to the part of the circuit
you are checking for continuity.
2 Connect one probe to one end of the component or
wire to be checked and the other probe to the other
end. It does not matter which way round the two
probes are placed.
3 Select the correct range on the multimeter.
a On the FLUKE 85.
Turn the switch to position 9-C and check that the
beeper symbol appears at the left hand side of the
display window. If the F sign is on instead, press
the button labelled 9-F in the meter drawing.
If there is continuity in the circuit, the beeper will
sound. If there is no continuity (open circuit), the
beeper will not sound.
b On the AV0 2003.
Move the right hand slider switch to position 10-B,
and the left hand slider switch to position 10-C.
If there is continuity (i.e. very low resistance)
between two points the buzzer will sound.
c On an analogue meter.
Turn the dial to the lowest Ohms (
If there is continuity (i.e. very low resistance)
between two points the needle will move across
fully (or almost fully) to the right hand side of the
scale.
C-8
Measuring Frequency
The AVO 2003 and the analogue meter are not capable of
measuring frequency, therefore a Fluke 85 digital
multimeter must be used.
1
2
3
4
5
Ω
) range.
9813/5100-1
Section C - Electrics
Overview and Schematics
Insert the black plug into the COM socket on the
meter and attach the probe to the nearest suitable
earth point on the chassis, for example, the battery
negative terminal.
Insert the red probe into socket 9-J.
Turn the selector switch to position 9-A and depress
9-G repeatedly until 9-F is highlighted on the top row
of the display.
Press button 9-H once.
Touch or connect the red probe to the frequency
source to be measured. Press and hold button if an
average reading is required.
Using a Multimeter
C-8