Infiniti i30 Battery and brake light stays on

[sm5coat]

I just received a 2001 i30from my mother since she doesn't drive any longer. The battery & brake lights come on go off at the same time for no apparent reason. I haven't noticed any adverse effects in the operation of the car but if I don't find problem the warning system is basically useless. Any ideas would be greatly appreciated.

Thanks

[MinisterofDOOM]

Usually when the brake and battery lights come on together, it's a sign of a charging system problem. Your alternator is probably failing. If you have access to a multimeter, you can test my suspicions. With the car running you should see over 14 volts at the battery terminals.

Assuming I'm right, you'll want to catch this one fast, or you might end up stranded in a random parking lot with a car that won't start (or stay started, since the battery is only for starting, while the alternator's what keeps the car running). I speak from plentiful experience on that point.

[loystock]

The 'Minister' is correct - the alternator is defective based on the symptoms provided. But you would like to eliminate other possibilities before replacing the alternator. Make sure the battery connections are clean and tight and that there are no crossed wires (short circuit), especially near the alternator mounting.

A good battery should read >12.5VDC with engine off and >13.8VDC with alternator charging (spec is 14.1-14.7VDC).

[sm5coat]

Thanks for the help. I finally got a chance to pull the alternator to have it checked and you were right, the voltage regulator was bad. I replaced it and everything is working great. Thanks again.

[loystock]

It's our pleasure to help. A lot of members seek help yet don't even bother to post back with result(s). You are one of the few.

[ronin_01r1]

I'm having the same issue although i had the alternator replace a couple years ago, so i'm guessing it's the regulator. i'm not so savvy with repairs so i'm planning to take it to a shop.

for me, instead of the lights staying on, they come on when the rpm goes above 3000, and turns back off below that. it just happened a few minutes from home so it's parked in the driveway now.

when i had the alternator replaced a couple years, it cost about $450 parts/labor. hopefully it doesn't have to be replaced already.

what do you think is the avg/ballpark rate (parts and labor) to have the regulator replaced?

thank you.

[loystock]

Welcome to NICO!

Take it to an electrical shop. Repair cost @ $100.