- Always perform a visual check for possible electrical system problems before attempting a diagnosis.
- Inspect all cables for broken or corroded wires, frayed insulation, or loose or damaged connectors.
Inspect the battery cables.
- A cable that is too short can rub against something until its insulation wears through, causing a short to ground.
The insulation can be worn away on a cable that is too short. Courtesy of Cooper Automotive/Belden.
- A cable that is too long and is not restrained properly can burn through an exhaust manifold.
- When there is high resistance in a battery cable or its connections, they will become hot to the touch. When resistance is within acceptable limits, cables and connections will not become hot. Resistance at the cable connections is a major cause of starting system problems. Check the condition of the terminals. Clean or replace them as needed.
Corroded battery terminals reduce the efficiency of the battery.
- Sometimes, a battery terminal does not have good contact with the terminal post or the cylinder block (in the case of the ground cable).
These cables do not have full contact with ground. Courtesy of Ford Motor Company.