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
- Wire brush or battery cable and terminal cleaner
- Protective eye wear and gloves
- 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.)
Step 3 - After the battery cable end has been loosened,
grasp the cable and twist to remove.
Loosen Battery Cable
Battery Cable Removed
Step 4 - Next, using a wire brush or battery terminal
and cable cleaner remove all corrosion by resurfacing both connection areas.
Step 5 - Once the battery terminal and cable end
have been cleaned reinstall the cable and tighten.
Clean Terminal and Cable End
Tighten Battery Cable
Step 6 - After the repair is complete, recheck
the problem and reinstall the terminal cover.
Once the job is complete retest the system, many other
Reinstall Terminal Cover
can emerge such
as dead battery
problems. Once the engine is running
to ensure proper operation.
When an engine is cranked over it demands a high amount of amperage from the
battery. As the electrical demand is increased heat will develop inside the
wire or connection. This heat will disconnect (short circuit) the electrical flow
until the connection cools. Since the battery provides the main electrical power
to the remainder of the vehicle (lights, dash, interior) all electricity is shut
off. Once the connection cools it can reconnect starting the process all over
The battery cable connection must be clean (free from corrosion) and tightly
fastened to the terminal to allow the flow of electricity from the battery to the
starter. Battery cable connections must be tight and not wiggle on the battery terminal.
If the cable is loose remove it to clean, then re-tighten the cable with a wrench
or socket wrench.
When a battery
internally, it can cause a loss of power, and then regain the power a short time
later. Inspect the battery of bulging it could have a warped plate that can short
under certain conditions. This problem is rare but it does happen.
Note: Never crank an engine over when anyone is near the battery or engine. A
battery is filled with explosive gasses that can ignite when extreme heat or a spark
is present. A battery could have residual acid on the outside casing so use caution
when handling a battery and the surrounding area. Use baking soda to neutralize
any suspected acid residue before work begins.
Article first published 2016-11-26