1. Advanced D-TAC Testing

2. D-TAC testing – Part 2 • This presentation is meant to be viewed after the introductory presentation ‘D-TAC testing – Batteries and Full System Tests.ppt’ has been viewed. • The first D-TAC presentation covers: • Basic battery testing • Advanced battery testing using the charging unit • Full system test that include battery, starter and alternator test

3. Advanced D-TAC tests • This presentation will cover using the D-TAC for: • Voltage drop testing • Multimeter functions • Inductive ammeter functions • Lab Scope functions • Infrared temperature measurement • Temperature probe [contact and immersion] temperature measurement

4. Test leads Adapter for DMM test leads Battery test leads Inductive ‘Amps Clamp’

5. Voltage Drop testing • Poor cranking and undercharged batteries can be caused by excess resistance in the cables connecting the battery positive terminal to the alternator and starter or the battery negative terminal to the engine block. • A voltage drop test can pinpoint resistance in the cables or connections by measuring the difference in voltage from cable end to end as current is passed through the circuit.

6. Conductance testing for circuit resistance • The D-TAC measures circuit resistance by conductance testing. • During the test the D-TAC inputs an AC electrical current into the circuit and measures the change in amplitude at it’s output • Unlike conventional voltage drop testing the ignition system does not need to be disabled and there is no need to place a load [using a VAT] on the battery during the charging system part of the test

7. Cable voltage drop test menu • The ‘Cable Voltage Drop” test is selected from the D-TAC’s main menu

8. Cable voltage drop test menu • There are 3 pre-set tests: • Battery Ground • Starter Circuit • Charging System Circuit • The ‘Other’ test allows the technician to setup the D-TAC to run circuit resistance tests on any automotive circuit • Start with the battery negative cable test

9. Battery test leads for cable-drop test • The voltage drop test requires that the battery test lead set be attached to the socket on the left side of the D-TAC

10. D-TAC test leads • For the ‘cable drop’ test the D-TAC’s built-in leads are connected to the starter and alternator positive and negative terminals • There normally isn’t any negative terminal on either the starter or the alternator – the test leads should be connected to a clean, unpainted surface on the starter and alternator housing

11. Set the battery ground amperage • The default setting is 80 amps which should work well for most 4 cylinder vehicles • Diesels and 8 cylinder engines can be set slightly higher

12. Battery ground - Initial test lead setup • The first part of the test establishes the battery voltage at the terminals and battery conductance

13. Connect battery cable test leads • Connect the D-TAC negative test lead to a good chassis ground

14. Second D-TAC test lead setup • Connect the red D-TAC test lead to a good chassis ground • If there is a pigtail lead on the battery negative cable connect the red D-TAC test lead to the chassis near where the pigtail terminal is bolted to the uni-body

15. Battery ground – Test results • The test takes only an instant – the results will show on the screen immediately

16. High resistance High resistance is usually the result of corrosion at the terminal ends If cleaning the terminal ends does not improve the resistance the cable needs to be replaced

17. High resistance on negative side Clean • If the test fails and the resistance is mostly on the negative side, remove and clean the battery negative terminal and the engine ground terminal • The engine ground terminal is usually located on one of the bolts that connect the engine to the transmission

18. Battery brush • When cleaning battery terminals the battery brush is used to clean the battery post and the cable end terminal

19. Battery brush • The inside surface of the terminal must also be cleaned

20. Starter circuit test • Return to the Cable Drop menu to select the Starter Test

21. Set the starter current • Most vehicles with 4 and 6 cylinder engines will use the default 150 amp setting • V8 and diesel engines should be set at 200 amp

22. Setup for starter circuit test Battery test leads D-TAC test leads

23. Battery terminal test lead reminder • The small battery test leads must be plugged into the socket on the left side of the D-TAC

24. Connect battery cable test leads • Connect the battery test leads to the battery cable terminal ends

25. Test lead position reminder • Connect the negative D-TAC lead to any un-painted and corrosion free surface on the starter housing

26. Connect D-TAC test leads • Connect red D-TAC test lead to the starter positive terminal and black D-TAC test lead to the starter housing [or engine block near the starter]

27. Starter solenoid terminal designations ‘B+’ terminal connects to battery positive terminal ‘S’ terminal connects to starter relay or neutral safety switch ‘R’ terminal rarely used on modern cars ‘M’ terminal connects to starter motor field windings or directly to the brushes on permanent magnet starters

28. Run the test • Press the ‘S’ button to run the test • The test will run in a second or less and display the test results for the positive and negative starter cables

29. High resistance on positive side Clean • If the test fails and the resistance is mostly on the positive side, remove and clean the battery positive terminal and the cable end at the starter B+ terminal • Use a battery brush to clean battery terminals and medium grit sandpaper to clean cable end terminals

30. Charging system test • Return to the Cable Drop menu to select the Charging System cable drop test

31. Set charging current • Most modern cars have an alternator that can produce about 80 Amps of current • Reset the current setting if the vehicle is equipped with an alternator that produces more than 80 Amps

32. Charging system test setup • The black D-TAC test lead should be clamped to a clean, un-painted surface on the alternator housing Fuse Box 100 Amp fuse

33. Charging system setup menu • The D-TAC will prompt you as to the position of the test leads

34. Test leads for the alternator • In most vehicles you will have to slide back the alternator output [B+] terminal cover to attach the test leads to the B+ post

35. Test leads remain connected to the battery • Make sure the battery leads are still connected to the battery positive and negative terminals

36. Battery terminal test leads • The battery terminal test leads are connected to the battery positive and negative terminals

37. Charging system - Test results • The test takes a second or two – then the results are displayed on the screen

38. Charging circuit cable drop test failure • If there is high resistance in the positive side of the charging circuit: • Check the cable connections at the alternator B+ post • Check the connections at the battery that provides current to the fuse box • Check for a loose connection or corrosion at the alternator fuse terminal sockets

39. Flat steel fusible links • If the vehicle uses flat metal fusible links – check connections for corrosion or looseness • Disconnect the battery negative cable before disconnecting fusible links • The fusible link for the alternator is usually the largest

40. Multi-meter Functions

41. Supported Multi-meter tests • DC Volts 0 - 40 volts • AC Volts 0 - 24 volts • DC Amps 0 - 700 amps - inductive • AC Amps 0 - 700 amps - inductive • Ohms • Diode test 0 – 1.5 volts • Infrared temperature -20 – 200 degrees F. • Direct contact temperature -20 – 200 degrees F. • Labscope single channel - no trigger function

42. Adapter for multi-meter test leads • The multi-meter test lead adapter must be connected to the socket on the left side of the D-TAC to measure volts, ohms and to use the lab scope functions

43. Inductive amps / clamp • The inductive amps / clamp adapter will be needed for DC and AC current measurements

44. Multi-meter Functions • Select the DMM from the main menu

45. Measuring voltage • Select Volts DC from the DMM [Meters] menu

46. Connect standard meter probes • The adapter allows you to connect standard multi-meter probes with banana plug terminal ends to the D-TAC

47. Test menu • The D-TAC reminds you to connect the test adapter

48. Auto-ranging • The D-TAC selects the proper voltage range to display based on the peak voltage measured during the auto-ranging process

49. Connect the probes to the circuit • Connect the probes to the circuit being tested

50. Voltage display • The voltage level between the black and red leads is displayed on the screen • You can use the volt meter function to perform convention voltage drop tests