Operation CHARM: Car repair manuals for everyone.

Initial Inspection and Diagnostic Overview


INSPECTION NOTES
1. Verify the customer's concern by operating engine to duplicate the condition.
2. Inspect to determine if one of the following mechanical or electrical concerns apply:
3. If inspection reveals obvious concern(s) that can be readily identified, service as required.
4. If the concern(s) remains after the inspection, determine the symptom(s) and proceed to the Symptom Chart. Symptom Related Diagnostic Procedures

MECHANICAL CHECKS
1. Preliminary checks to charging system should be made regardless of the fault condition. These checks include:
a. Check alternator drive belt to ensure proper tension and no slip between alternator pulley and the drive belt.
b. Check battery for full charge.

ELECTRICAL
1. Before performing charging system tests on the vehicle, note conditions such as: slow cranking, discharged battery charge indicator lamp stays on with engine running, charge indicator lamp does not illuminate with ignition switch in RUN and engine not running. This information will aid in isolating the part of the system causing the symptom.
2. When a relatively new battery is discharged, test for current drain. The following are some of the most common current drains:
a. Glove compartment lamp stays on with door closed.
b. Engine coolant lamp stays on constantly.
c. License plate lamp or interior lamp stays on constantly.
d. Other electronic component malfunctions.
3. Check the fuses/fuse links to alternator to make sure they are not burned or damaged. This condition, resulting in an open circuit or high resistance, can cause erratic or intermittent charging system concerns.
4. Check battery posts and cable terminals for clean and tight connections.
5. Clean posts and the cables to ensure good electrical contact.
6. Check for secure connections at alternator output, voltage regulator and engine ground. Also check the connection at power distribution box.