Charging system issue

L.M. BEECH

MEMBER
1998 NISSAN FRONTIER
4 CYL
2WD
AUTOMATIC
154,400 MILES

The alternator went out so I changed it with a refurbished one. It would not charge the battery so it was tested on the truck and was putting out 11.8 volts, but tested at 14.0 volts off the vehicle. I have also replaced the bus fuse between the battery and alternator and still the battery goes dead. Will you please tell me what to do next? Thank you sir.

1 Reply

MOTOR MASTER

MECHANIC
279 POSTS

Hello my name is Dave.

It sounds like you could still have an issue with the alternator. First thing I would suggest doing would be to disconnect the negative battery cable and connect a test light between the battery post and the cable, if the light lights up you have a drain, however you have to be sure nothing else is on such as interior lights or under hood light (if it has an under hood light unplug it or take the bulb out). The next thing I would do is to disconnect the main wire from the alternator and see if you still have a drain. If the light goes off after you disconnect the main wire then the alternator is draining the battery and should be replaced. If these tests show that the alternator is not draining the battery then you would have to perform further tests. However, if you did not have an issue with the battery draining before you replaced the alternator then I feel that is by far the most likely issue. Let me know if you need to further trouble shoot and I will be happy to help in any way I can. I hope the helps you find the issue and thank you using 2CarPros.