'07 Nissan Quest -- Battery + Brake Light Showing -- ALTERNATOR ISSUE!

craftsman wrote: ↑ Sounds like a bad alternator. However, now is a good time to clean up all of the connections and get everything checked/tested before Winter hits.

I would:

1. disconnect the battery's and the alternator's electrical connections, give them a good cleaning, apply some dielectric grease, and tighten everything back up.
2. Check/fill the battery fluid levels if you can
3. Charge the battery with an external charger.
4. Check the alternator's belt to ensure that it's tight and in good condition
5. Bring the car to someplace that can test both the battery and the alternator to be sure - most places will do that for free so you have nothing to lose.

rosario99 wrote: ↑ I own a 2007 Nissan Quest S. For the past few days i've been seeing the Battery Light and Brake Light showing. The DRL lights are also flashing. My understanding is there is a car battery issue, in particular the Alternator / Generator issue.

I attached my multimeter to the car battery's POS and NEG posts and it reads:

Before Ignition: 13.05v
After Ignition (car running): 12.47v

I did not add any special load such as AC, high beams, radio.

NEXT i attached the NEG lead of the multimeter to the NEG post of the battery and the POS lead of the multimeter to the POS post of the Alternator. It reads:

Before Ignition: 13.16v
After Ignition: 12.55v

NEXT i attached the POS lead of the multimeter to the POS post of the Alternator and, while the car was running, i attached the NEG lead of the multimeter to the POS post of the battery with the point being to see if there was power running from the Alternator's POS post to the POS post of the battery. It reads: 0.00v

NEXT i attached the POS lead of the multimeter to the exterior case of the Alternator. The NEG lead of the multimeter was attached to the NEG post of the battery. It reads: 0.02v

What does all this mean? Do i have a break in the wiring? Bad alternator? Bad Fuse?

I'd appreciate further steps to diagnose the exact problem

Thanks

fusion2k2k wrote: ↑ Is the battery good? I had similar symptoms on a 4yr old car and it was a failing battery.

qaz393 wrote: ↑ you have successfully measured the voltage drop between alternator and battery.

rosario99 wrote: ↑ I own a 2007 Nissan Quest S. For the past few days i've been seeing the Battery Light and Brake Light showing. The DRL lights are also flashing. My understanding is there is a car battery issue, in particular the Alternator / Generator issue.

I attached my multimeter to the car battery's POS and NEG posts and it reads:

Before Ignition: 13.05v
After Ignition (car running): 12.47v

I did not add any special load such as AC, high beams, radio.

NEXT i attached the NEG lead of the multimeter to the NEG post of the battery and the POS lead of the multimeter to the POS post of the Alternator. It reads:

Before Ignition: 13.16v
After Ignition: 12.55v

NEXT i attached the POS lead of the multimeter to the POS post of the Alternator and, while the car was running, i attached the NEG lead of the multimeter to the POS post of the battery with the point being to see if there was power running from the Alternator's POS post to the POS post of the battery. It reads: 0.00v

NEXT i attached the POS lead of the multimeter to the exterior case of the Alternator. The NEG lead of the multimeter was attached to the NEG post of the battery. It reads: 0.02v

What does all this mean? Do i have a break in the wiring? Bad alternator? Bad Fuse?

I'd appreciate further steps to diagnose the exact problem

Thanks