Charging system – check

Note: These vehicles are equipped with an On-Board Diagnostic-II (0BD-10 system that is useful for detecting charging system prob­lems because it can provide you with the Diagnostic Trouble Code (DTC) that will indi­cate the general nature of the problem. Refer to Emissions and engine control systems for a list of the DTCs used by the PCM/ECM on these vehicles and for the pro­cedure you’ll need to use to obtain DTCs.

1. If a malfunction occurs in the charging circuit, do not immediately assume that the alternator is causing the problem. First check the following items:

a) The battery cables where they connect to the battery. Make sure the connec­tions are clean and tight.

b) The battery electrolyte specific gravity (by observing the charge indicator on the battery). If it is low, charge the battery.

c) Inspect the external alternator wiring and connections.

d) Check the drivebelt condition and ten­sion (see Tune-up and routine maintenance).

e) Check the alternator mounting bolts for tightness.

f) Run the engine and check the alternator for abnormal noise.

2. Using a voltmeter, check the battery voltage with the engine off. It should be at least 12.6 volts with a fully charged battery.

3. Start the engine and check the battery voltage again. It should now be greater than the voltage recorded in Step 2, but should not read more than 15 volts.

4. If the indicated voltage reading is less or more than the specified charging volt­age, have the charging system checked at a dealer service department or other properly equipped repair facility. The voltage regulator on these models is contained within the PCM and it cannot be adjusted, removed or tam­pered with in any way.