jcb 1CX, Service Manual

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Section C Electrics
9803/8550
Section C
Test Methods 2 - 1 2 - 1
Issue 2*
Use Of Multimeter
In order to obtain maximum benefit from the fault finding information contained in Section C it is important that the technician
fully understands the approach to fault finding and the use of the recommended test equipment, in this case an AVO 2003
digital multimeter, or a moving pointer (analogue) multimeter. The approach is based on a fault finding check list. In tracing the
fault from the symptoms displayed you will be directed to make measurements using a multimeter.
These instructions are intended to cover the use of the recommended multimeters.
1 Make sure that the test leads are plugged into the correct sockets. The black test lead should be plugged into the black
socket (sometimes, this socket is also marked by a " – ", or "E" or marked as "COMMON" or "COM"). The red test lead
should be plugged into the red socket marked with "+", "V" or " ".
2 When making measurements ensure that the test probes have a good clean contact with bare metal, free from grease, dirt,
and corrosion as these can cause a false reading.
3 When measuring voltage:
Make sure that the correct range is selected, that is set the selector to a value equal to or greater than that you are about
to measure. e.g. If asked to measure 12 Volts, set the selector to the 12V range. If there is no 12V range, set the selector
to the next range higher, 20V for instance.
If the meter is set to a range that is too low, it may be damaged.
e.g. setting to the 2V range to measure 12V.
AVO 2003 A typical analogue meter
A
OFF
V/A
V/A
A171900
A171890
A
B
C
*
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