shwalker07

I have been having a issue with my 04 GS300. I was driving in the evening with all the electronics on (headlights, foglights, a/c on full, rear defrost on, radio on...) and when I came to a stop at a light, my battery light came on and the interior lights were dimmer than usual and the radio was flickering and turning on and off. Right away I started to turn off the electronics starting with the rear defrost and a/c and then the battery light turned off and the radio went back on and the interior lights were bright again like they should be. This was all still while the car was at idle and stopped at the light. So with most cases with the battery light on usually that is a charging issue so I took alternator out and tested at 3 places and 2 said it was good and napa said it was bad. With out taking a chance I ordered a re-manufactured Desno alternator from rockauto and it's been 2 days with the new alternator installed and it has been doing the same thing when at idle with all the electronics on. The battery connections, terminals and cables are in mint condition and tight as well. The vehicle is still drivable but you just cannot have all the electronics on at once.

Next I am going to test the battery but I was wondering if anyone else ran into a problem like this? Also there is no aftermarket speakers or anything else installed in the vehicle. Thanks again everyone.

GS400V8

iTrader: (4)

Yes, the battery should be tested. Especially if there is a short between two or more plates in the battery. This can cause very low resistance and have the effects you are describing. Often times I have put new batteries in people's cars before charging them money to see if it is the alternator or not. Some times it is the battery even though symptoms showed the opposite. Although, vice verca can occur.

MikeFoxx

iTrader: (8)

Yeah alternator and battery should always be checked together when stuff like this happens. When first reading I initially thought alternator... surprised no one from the 3 locations offered to test the battery. Good luck hopefully a fresh one does it and you'll be good on that for several years.

lexo98

iTrader: (2)

My alternator lasted till about 235k and I have a sound system. My battery however has been replaced multiple times. One time that I had issues similar to yours my Yellow top Optima battery was shorting out

shwalker07

Thanks everyone for the response. I got the battery tested today and it did test bad so I am putting a new one in and it should be good. I know the oem Denso alternators usually last a long time and I still even have the original in my 87 Supra. I'm thinking Napa did not test the alternator right or they just did not know what they were doing. Thanks again everyone.

tcbernert

I had the same problem and after a few days I found the problem was the ground leaving the alternator. I found the cable was coming loose because I didn't get a new nut so I used the old one. after inspec I noticed it was loose and the plactic seating was cracked. so I replaced the nut put two washers on and got a tight fit. 5 days so far so good. If theres not a good ground at the battery the connection heats up and electrons change the charge going back to the battery. my gx470 has a 100 amp alternator and that can heat up fast.

eicca

I had a battery that "tested" fine but would still occasionally trigger the battery light on the dash. When I put a new battery in, the car cranked noticeably stronger.