Mechanics

Clean Battery Cables - Electrical Goes Dead

Step by step repair guide on how to fix an automotive electrical system that goes dead when the engine is cranked over. This article pertains to all vehicles.

Difficulty Scale: 3 of 10

Tools and Supplies Needed

  • Flashlight
  • Wire brush or battery cable and terminal cleaner
  • Protective eyewear and gloves

Step 1 - For electrical energy to flow all electrical connections must be secure and free from corrosion, this is especially true for high amperage draws such as an engine starter. When currant demands are low such as interior lights the circuit will work just fine, but when the ignition key is turned engaging the starter, the circuit shuts down due to heat, and then reconnects once cooled. This condition is common for the positive terminal and cable of the battery. Neutralize battery acid using baking soda and rinsing with water before work begins.  (Note: Record radio stations for re-entry once the battery is replaced. Neutralize any battery acid by sprinkling baking soda over the top and around the battery base, rinse with fresh water to remove any lingering acids.) (CAUTION: Never connect positive and negative terminals with a conductive object such as a wrench. Also, never connect the positive battery terminal to any body, chassis or engine parts.)


Battery Terminal Corrosion

Step 2 - Once the terminal and battery cable have been cleaned, use a small socket or wrench to loosen the cable end (key OFF.)


Loosen Battery Cable

Step 3 - After the battery cable end has been loosened, grasp the cable and twist to remove.


Battery Cable Removed

Step 4 - Next, using a wire brush or battery terminal and cable cleaner remove all corrosion by resurfacing both connection areas.


Clean Terminal and Cable End

Step 5 - Once the battery terminal and cable end have been cleaned reinstall the cable and tighten.


Tighten Battery Cable

AUTHOR


Written by
Co-Founder and CEO of 2CarPros.com
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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Article first published (Updated 2013-11-28)