T h e r e    a r e    t w o    c o m m o n    c i r c u i t    r e s i s t a n c e tests—insulated  resistance  test  and  ground  circuit resistance  test. Q1. INSULATED   RESISTANCE   TEST.—To perform  an  insulated  resistance  test,  connect  the  load tester   as   described   by   the   manufacturer.   A   typical connection setup is shown in figure 2-35. Note how the voltmeter  is  connected  across  the  alternator  output terminal and positive battery terminal. With  the  vehicle  running  at  a  fast  idle,  rotate  the load control knob to obtain a 20-amp current flow at 15 volts or less. All accessories and lights are to be turned OFF.  Read  the  voltmeter.  The  voltmeter  should  NOT read   over   0.7-volt   drop   (0.1   volt   per   electrical connection)  for  the  circuit  to  be  considered  in  good condition.  However,  if  the  voltage  drop  is  over  0.7 volt,  circuit  resistance  is  high  and  a  poor  electrical connection  exists. Q7. G R O U N D    C I R C U I T    R E S I S T A N C E TEST.—With  the  ground  circuit  resistance  test  the voltmeter leads are placed across the negative battery terminal and alternator housing (fig. 2-36). The voltmeter should NOT read over 0.1 volt per electrical  connection.  If  the  reading  is  higher,  this indicates  such  problems  as  loose  or  faulty  connections, burnt plug sockets, or other similar malfunctions. Figure 2-35.—Typical insulated resistance test setup. Figure 2-36.—Typical ground circuit resistance test setup. 2-24 Q2. Q3. Q4. Q5. Q6. Q8. Q9. Q1O. Q11. Q12. Q13. Q14. Q15. Q16. Q17. Q18. Q19. REVIEW  1  QUESTIONS How  many  electrical  circuits  are  in  a  typical automotive electrical system? What  component  of  the  charging  system produces and stores electricity? What substance is contained in apositiveplate of a  filly  charged  battery? What type of gas collects at the top of a battery? What  is  the  specific  gravity  of  a  fully  charged battery? What  are  the  two  methods  of  rating  lead-acid storage batteries? When  mixing  electrolyte,  you  should  follow  what rule? What  battery  test  will  determine  if  current  is discharging across the top of the battery? You are performing a battery drain test using an ammeter.  What  should  the  meter  read  with everything in the vehicle turned off? When performing a quick charge test, you should charge  the  battery  at  30  to  40  amps  for  what minimum time period? What are the two types of field circuits used in dc generators? What  are  the  three  design  factors  that  determine the output of a dc generator? What two tests are used for locating shorts in the armature of a dc generator? What component of the alternator contains the heat  sink  the  diodes,  the  diode  plate,  and  the electrical terminals? What  type  of  alternator  stator  is  used  in  high output alternators? How  is  alternator  output  reduced  using  an electronic voltage regulator? What   is   the   most   common   type   of   voltage regulator used on modern vehicles? What   charging   system   test   measures   the charging systems voltage, under low output, low load conditions? What two testing devices are used to perform a charging system test?