My battery light and brake light goes on , some time goes off and on / I have a new battery and I change the altalnator

Try changing the bulb.

Your battery could have a loose connection,follow the negative cable and see if it is getting a good connection.

When the brake light and battery light come on at the same time on a Nissan, it is most likely the alternator. Perhaps you got a faulty alternator or it has failed already. Another possibility is a bad connection from alt. to batt.

check the fluid again,, if the brake pedal feels spongy at all,, you have air in the lines still, if so , bleed the brakes,, unhook the battery to clear the light, and try again

Emergency brake may not be all the way off .Also thelow leval brake fluid sensor might need attention....check the fluid in the master cylinder and if thats good ,unplug the sensor at the brake fluid resivor and see if light goes out

Im having the same issue on my 04 Quad Cab Dakota. Changed out the brake light switch but still no brake lights. You have any luck ?

The most likely cause if you have changed batteries and replaced the alternator is that you have something that is an electrical drw when the car is shut off.

I assume the battery goes down while the car is sitting?

If it goes down when you are driving, it is likely a different problem.

If you don't have a multimeter to check for current draw when everything is shut off, an easy test to remove the negative battery cable and let it set the time it takes to discharge.

Then hook it back up and see if you have a full battery. If it doesn't go down with the batteryt cable disconnected, you either have a short somewhere or there is something left on (like a glove compartment or trunk light) that is draining the battery.

I assume you checked for the obvious things like brake lights staying on when the car is shut off (brake light switch problem).

Time for a new car. OK battery gauge sounds like a loose belt or bad alternator. Brake pedal return spring maby broke or missing. check gauges is usually indication like the idiot light light. good luck

Hi Peters6709,
Sorry to tell you, but you need to replace the pad-wear sensors as well. They are the little trapezoid pieces that hang inside the tops of the inside pads. They should run about $10 each. Once replaced, disconnect the battery completely for about 10 minutes, if you have a stock radio keep the code handy.

Next time check the pads every 10-12K miles. I have been running the SAME pad wear sensors on my Z3 for the past 2 pad changes now after making the same mistake the first time.

Best of luck!

sound like battery weak.have battery and alternator checked out.