Measure key-off battery drain (parasitic draw).

Measurement should include

  • using an ammeter, according to manufacturer standards
  • diagnosing the cause by isolating the excessively drawing circuit by disabling/disconnecting portions of the circuits or components (methodically from maxi fuses to mini fuses)
  • diagnosing the causes of abnormal key-off battery drain
  • determining needed repairs.

Process/Skill Questions:

  • What is the typical allowable range for a parasitic draw?
  • What is key-off load?
  • How would a technician perform a parasitic draw test? Why is this test conducted?