TM 10-3930-669-20 CAUTION Use proper sized test leads when checking for resistance, continuity, or voltage at connectors or damage to equipment can result. NOTE ·    Multimeter leads must remain in contact with the circuit being tested for a minimum of three seconds to obtain a reading. ·    If your multimeter does not operate in the way described in the following steps, learn how it operates before performing troubleshooting. ·    The  piece  of  electrical  test  equipment  used  will  be  referred  to  as  the  "multimeter."  The multimeter's  red  test  lead  will  be  referred  to  as  the  "positive  (+)  multimeter  lead."  The multimeter's black test lead will be referred to as the "negative (-) multimeter lead." (1)    Resistance and Continuity Measurements. (a)  Connect  positive  (+)  multimeter  lead  to  multimeter  VOLT-OHM  connector.    Connect  negative  (-) multimeter lead to multimeter COM connector.  When the multimeter leads are separated or are measuring a circuit with no  continuity,  the  multimeter  will  indicate  "OL"  (Over  Limit)  on  its  display.  When  multimeter  leads  are  connected together, multimeter should display "0," indicating a continuous circuit with no (zero) resistance. (b)  Set  multimeter  function/range  switch  to  the  desired  ohm  position.    If  the  amount  of  the  expected resistance is not known, set the switch to the highest range, then reduce until a satisfactory reading is obtained.  If only continuity  is  to  be  checked,  without  regard  to  resistance,  set  the  multimeter  function/range  switch  to  the  highest  ohm range. (c) Always turn the main power switch to the OFF position before connecting multimeter leads to a circuit unless instructed to do otherwise in the troubleshooting procedure. (d) Connect multimeter leads to the circuit being checked.  The multimeter leads must only contact the point of measurement to ensure an accurate reading. (e) Read the resistance value displayed on the multimeter. (f) Disconnect multimeter leads from circuit. (g) Turn off multimeter. (2) Voltage Measurements.  The forklift is equipped with a 24-volt electrical system.  Troubleshooting procedures will reference 24 vdc measurements; however, these values can vary depending on battery conditions and if the engine is running or not.  If battery voltages are below 12 vdc, charge batteries. (a)  Connect  positive  (+)  multimeter  lead  to  multimeter  VOLT-OHM  connector.    Connect  negative  (-) multimeter lead to multimeter COM connector. (b)  Set  the  function/range  switch  to  the  setting  closest  to,  but  not  below,  24  vdc.    If  multimeter  is equipped with a DC-AC switch, set the switch to the DC position. 2-11