Hi All,
Have a 94 Altima EX, 230K miles, with brake and battery dashboard lights on. Replaced old alternator with good known bench tested alternator but brake and battery dashboard lights still on. Any advice is most welcomed.
Thanks,
Andy

Hi Andy!
Bummer to hear about your car man.
Do you have any other troubles, or does the car work just like it should? Is it charging? Do the brakes work? Have you tried disconnecting the battery, waiting 10 minutes, and re connecting to clear it?

You may want to check out the FSMs that we have Factory Service Manuals available free to members. Take a peek at the link in my signature and find the FSM for your car and you'll have all the info you'll ever need to make the repair and try to diagnose it for yourself while help is on the way.

The battery light in an Altima is any charging system fault. If it is not the Alternator, it could be a bad connection or bad battery etc. A voltmeter at the battery can tell you if the voltage is out of the normal 13-14 volt range.
If your car still drives, you might be able to get some free tests from any auto shop or auto parts store.

Thanks for your input. I wanted to also mentioned that when I press the brake pedal my dash board clock light goes off. When I release the brake pedal my clock goes on again. Don't know if this is related or not?

Dash lights dimming would suggest not enough electrical current to run both the headlights, dash lights and when you press the brakes, the brake lights too. With the car off, do you have 13 volts at the battery? Can you start the car, disconnect the battery and have the engine continue to run? Do your headlights dim when you press the brakes? Do your best lights actually come on?

acuevas123 wrote:Thanks for your input. I wanted to also mentioned that when I press the brake pedal my dash board clock light goes off. When I release the brake pedal my clock goes on again. Don't know if this is related or not?

Did you ever figure this out? My 93 GXE does the same thing. Not all the time, just intermittently. And when it does, apparently the driver's side brake light does not light up. When I brake and the clock stays on, the brake lights work fine.

Mat, I don't have a resolution to Acuevas123's issue.
There are some tests you can do. Try using a voltmeter to measure battery voltage while the brake is depressed and the dash lights are going out. This light usually points out a bad alternator or battery. But, don't go buy one without testing the old one just in case your problem is more complex. Most auto parts stores will do free testing, and the Altima alternator is easy to access as it's near the thermostat and also serves as the belt tensioner. Also look for patterns like night driving, heat, any pattern to this issue.

Appreciate the input. Ironically, I just replaced the alternator a few months ago and the battery is also only a year or two old but the intermittent brake light issue was happening way before the battery and alternator replacement and still happens. The odd think is that it is only the driver's side brake light that fails, and when it does, the digital clock dims out.

I have looked for patterns and found none. Happens during the day and at night.

Only the driver side brake light goes out.....
That's a good clue. When one light turns another off, the problem is usually a bad body ground. The taillight and dash lights might be grounding through the Brake light power feed. When the brake lights come on, there is no longer a ground path.
Check for two things, a bad taillight bulb--try swapping from the other side--and the ground on the taillight circuit. Should be in the fender near the taillight housing. If those are good, it might be a problem with the headlight switch.

A volt meter can also tell you if you are getting power to the lightbulb socket. You could also have a short in the brake light wiring, but if that is the case all lights should dim equally. Still think it's a ground issue or a bad bulb.

Hey Guys,
Thanks for all the input. I had placed this issue on the side momentarily. Got busy with other more pending stuff on this vehicle. (i.e. Overheating with no visible leaks.)

Does anyone have a link on how to use a volt meter to check these issues. I don't understand the actual logistics on how to go about using a meter to check the various current levels.