INTRODUCTION
MINI 97MY
1.2
Caution: Before undertaking any electrical work on a vehicle
ALWAYS read the ELECTRICAL PRECAUTIONS detailed on the
next page.
Battery voltage
Before commencing diagnosis of electrical problems verify the condition of the
battery is acceptable by using the open circuit voltage test.
Open circuit voltage test
Switch off all electrical loads on the vehicle.
Adjust digital multimeter to read d.c. volts on the appropriate scale.
Connect test probes across battery terminals ensuring that polarity is correct and
record the voltage displayed.
NOTE: If the vehicle has been used within a period of 8 hours
prior to the test, surface charge must be removed from the battery
by switching the headlamps on for approximately 30 seconds.
Wait a further 60 seconds before checking the open circuit voltage.
Battery voltage is used as a known reference for ascertaining whether or not
circuits are receiving sufficiently high voltage for components to function
correctly. This reference is only a guide since most electronic circuits are
designed to function over a wide range of voltages. In addition, consideration
must be given to readings affected by voltage drop across certain components
and fluctuations due to cable lengths.
A reading of 12.3V or more is acceptable; any battery which
reads less than this will need charging.
