I bought an alternator from autozone and installed it. The other day when I started the car up the battery/brake lights came on briefly then went out. Today the same thing happened. I brought my car to a nissan dealership that told me aftermarket alternators can overheat which is causing the light to go on... and this could cause my car to break down. Is this bull or do I need to spend the extra 200$ for a NISSAN alternator? Thanks

 

That's false.

As for your issue...how's your battery? I replaced both of mine 2 weeks ago at the same time, haven't had issues.

Make sure your connection to the alt is good (that one wire that you screw into the alt).

 

Battery is brand new replaced it at the same time as the alternator, also replaced the alternator belt. The light didn't come on for the first week but the last two days it did so I panicked and brought the car to Nissan.. bad idea. I checked that screw and it's in the right. Any ideas what else it could be? Nissan did a diagnostic and didn't find anything, they just said the alternator so I'm clueless.

 

How's your belt tension?

 

Maybe try tightening your belts? Maybe you didnt put enough tension on it and its slipping a bit when you first start the car.

I could c this maybe tripping your car out a little thinking its not getting charge untill it grips the belt...

 

had to replace my alternator from autozone after a week... yay reman'd alternators.. replacement has held up though :knockonwood:

 

I checked the belts and the tension seems to be good. The past two days the lights haven't come on but since I've put the new alternator in the air bag light will come on at startup for a few seconds then go out. Any idea what that could be?

 

yes - normal operation

 

My alternator just went out last week, (it was a reman) the previous one was only a year old, I replaced the original only because the bearings were noisy. I too, got mine at Autozone for the warranty. Miine was oil soaked from engine. I have since fixed oil engine leak (rocker cover gasket was shot). The Battery and Brake dash indicator lights came on to alert me to the failing alternator, they would go off when the engine RPM rose above 2K and would come back on around 1.5K. Autozone hooked up there tester and the guy told me it was the alternator. I'd take it to them and have them check it. Also it it getting oil soaked?

 

Its is also possible you purchased a bad alternator. Take it back and have it tested.

 

I brought 2 alternators from Pep Boys and they both went bad. Ever since I always have them test the alternator/battery/starter before I even leave the store.

 

Update: So roughly 2 weeks later the battery/brake light still come on sometimes. Yesterday driving it came on for a few minutes then went out. Am I going to have a problem down the road or could this just be the alternator getting broken in?

 

mmm i had a similar problem but the alt is fine mmm u should check the brake thingi that send the signal to ur break lights mines would of alway be on and it was that screw that sends the signal to the break light...... other than that if ur car starts fine if in idle doesnt act funny.. is deff working properly but if u have a bad system please use a capacitor i messed up 2 alts in 2 months.

 

A basic check would be checking voltage across the battery terminals (especially when you first start the car, since that appears to be your major issue). At slow idle, you should be getting in the high 13's if the alternator is working right. As RPM goes up, you should be getting somewhere around 14.2-14.4. I think the FSM has a chart for alternator output voltage at the battery vs RPM.
AutoZone or Advance Auto can also check them (another basic test) while its on the car.