Battery light on

I have 95 sentra and the battery light and brake dash lights are on.I checked the battery when runnig and I got 11.75 which tells me its not charging.If I pull the emegency brake the brake light gets about 1/2 again brighter than when its not on. Do I have a bad alternator or possible wiring harness problem (had a bad body ground on a chevy do dumb things like that once) and how will I be able to test. Thanks

My car had the same symptom, but it never actually died. Mine seemed to be a random short. Lights would go on for a while and then off.

This can be caused by a faulty alternator causing a short. Those two lights are wired such that when a short is caused by the alternator they will go on.

I installed a multimeter on the alternator output so I could monitor the voltage while driving. What I noticed is that most of the time it would stay on 14.2 more or less (which is quite normal) but occasionally it would quickly jump to something aroung 19 volts.

I replaced the alternator and it's been alrite now.

Before replacing the alternator, check for loose belt: the alternator pulley may be sliping.

While the engine is running, measure the output of the alternator. Some voltage should come off of it. If not, check the connector that feeds the field voltage.
- check for a blown fuse
- disconnect the negative terminal and check for continuity from the alternator output to the battery positive: it should read 0 ohms

Even if everything seems fine, it may be that the voltage regulator is not functioning ok. In this case, it should be taken to a store for a testing. (yeah, autozone will test it for free...)

do you know anything about 200sx nissans

dang adelara like a human FSM lol

fredo

Sorry.... know nothing about 200SX except they look cooler than my plain GXE

200sx same as sentra wuts seems to be the problem??

fredo