Nissan Sentra

I have a 1998 Nissan Sentra automatic with 135000 miles. About two weeks ago th battery and brake lights in the dash started blinking. The car was running fine so I didn't do anything. Then my battery died. I had the car checked to see if it was the alternator but they said it was just the battery so I got a new battery but the lights are still blinking. What else could be draining the battery if the alternator is working?
October 30, 2007.

Get a voltmeter-hook it up to the battery-record the reading before you start it up-Now start it up-read the meter again-is it between 13.5 and 15.5 volts if not its not charging-if its over then its killing the battery by overcharging it.

Drain testing-disconnect one battery cable put meter in between follow polarity do you have a reading. Be advised allowable milliamps should be less then 0.030 anything over you have an excessive draw. If so start removing fuses/relays/circuit breakers/connectors-the one that eliminates the draw is the problem circuit.

Oct 30, 2007.
I have a 1994 Nissan Sentra (100K miles) with a very similar problem. A few months ago the battery and emergency brakes began flickering whenever the car was on. This was accompanied by an annoying fast clicking noise occassionally. My mechanic looked at it and could find no problem. Today when I went to get into the car, I noticed the battery light was on eventhough the car was off. The car wont start now and is acting as if it needs a battery replacement. Could the flickering lights have killed my battery. Otherwise the car has been running perfectly for years.

Oct 30, 2007.
For both of you, look below in the charging system EWD

For the alternator light to come On or flicker and wiring is okay. Check the internal voltage regulator in the alternator. This the one controls the alternator output.

If battery is in good conditon which is the only way to find out is to do a battery capacity test on it-if it can hold up 9.6 volts or better in 10secs its good to go, if not it needs a replacement.

Double check all connections involving the battery and alternator

Oct 30, 2007.