I noticed this has been happening on and off for the past couple days. The battery light turns on when coming to a stop/applying brakes. The battery is 10 months old, the alternator is 2.5 years old. I checked the terminal connections and everything is tight and corrosion free, I use marine type brass connectors.

Any thoughts?

 

I had this exact same problem on my Escort. Thought it was the battery but it was actually the alternator. There was a loose wire on it and I had to snip it, crimp on a spade plug and it's good as new. Check the wires on the alt.

 

Thanks for the idea! I'll check the wiring.

 

Happened to me on the ES 300 on the highway in a blizzard...bad alternator. Get it replaced or it will leave you stranded. I was lucky. Get it checked out at the zone.

 

CHecked the wiring around the alternator and all is tight and secure so I'm leaning toward the alternator going out as well. I already purchased one online the same day I posted here to make sure I had one sitting around in case it ended up being that.

Thanks!

 

If you want to be super certain, pick up one of these. Cyberdyne Voltmeter. It plugs into the cigarette lighter.

When the car is off, it give you the volts of the battery to let you know if you have enough juice to crank it over, perfect for pulling a car out of storage.

When the car is on, it gives the volts from the alternator. I had a bad alt and was going to a friends house to fix it and I got stuck at a light and watched it drop from 12 down to 11, then down and down and down. I made it there, barely.

http://www.cyberdynegauges.net/Details/rplugvolt.html

http://www.cyberdynegauges.net/voltmetersproduct.php

Ebay has these which are essentially the same thing. Not bad wither, under 15 bucks.

http://cgi.ebay.com/Car-Truck-Voltme...item2306adff9d

or you could just use a regular multimeter.

 

Yup, the voltage test will help you figure things out. I'd test the voltage at the battery and at the alternator post just to make sure the wiring isn't the culprit before you replace the alternator. Odds are it's the alternator but if it happened to be the wiring like McKrevice had happen, it'd save you a good chunk of change and time.

 

Yeah i agree on this, it's a sign or alternator is dying out. seen this happen before. as i believe...

 

Getting the charging system checked out properly..

 

had a similar issue, try reading this thread too.
https://www.clublexus.com/forums/gs-...s-off-wtf.html

 

The battery light was turning on more and more often, then last night I'm 3 blocks away from home and the Navi screen starts blipping off, thats exactly what started happening 2.5 yrs ago when the alternator went out. Hurried home last night, 1.5 hours later I had the new alternator put in and all is good again.

Last time and this time again I picked up the rebuilt alternators they sell on eBay for $100. If they last me 2.5yrs each I'm still way ahead from paying $400 from the autoparts store, or $700 at the dealer, lol.