A properly working charging system puts out about 13.2 to 15.0 volts. A battery should have a static charge of 12.3-12.8 volts when the engine is shut off. If a battery is not good, the charging system may not be able to charge properly. If a vehicle is not charging properly and the battery is good, the first thing to do is to turn the ignition switch to the "ON" position without starting the engine and make sure the charging system warning light is operating. If the bulb is burnt out, the charging system will not charge. If the bulb is OK but still does not illuminate, the circuit must be tested. If the warning lamp does illuminate, then the next thing to check is to make sure the circuit between the battery positive post, or fusible link, to the connection in back of the alternator is good. On Nissans, this will be a thick (approx. 10 gauge) wire to the "BAT" post on the back of the alternator. It's not uncommon for this wire to get corroded and burn up, creating resistance in the circuit. So, before assuming an alternator is bad, make sure this circuit is good and battery voltage is getting to the alternator. It's also important to make sure the alternator belt is tight and not slipping and the battery connections are clean and tight. Do a voltage drop test between the positive battery post and the alternator post (should be below 200mV) and the negative post to the body and block (both should be under 50mV).
When replacing electrical components such as alternators, starters and distributors, fuel injectors and sensors, always replace with new or reman'd Nissan OEM components; aftermarket components generally don't last long, don't work right and many times are DOA.
When replacing electrical components such as alternators, starters and distributors, fuel injectors and sensors, always replace with new or reman'd Nissan OEM components; aftermarket components generally don't last long, don't work right and many times are DOA.
