Battery Light Warning
Recognized HCF Member
Joined: Sep 2007
Posts: 9,453
From: Houston, Texas
RE: Battery Light Warning
That1Guy, this is most surely an alternator problem. If the alternator belt is tight and not slipping, then I highly recommend that you replace the alternator with a new or rebuilt one. If you are interested, rebuilt alternators from AutoZone come with a life time warranty.
Recognized HCF Member
Joined: Jun 2007
Posts: 10,023
RE: Battery Light Warning
Turn the key on (no need to start the engine) and make sure you have battery voltage on the "B" wire on the 4 pin connector going to the alternator. Not having that power is one of a very few things other than the alternator itself that can cause the symptoms you have.
If you take the alternator out of the car, some places can test it on the bench. The regulator is built into the alternator and they are typically replaced as a unit. I would say there's about a 95% chance the problem is inside the alternator/regulator assembly. There are some people who work on the insides of alternators but most prefer to just swap it with a rebuilt one.
If you take the alternator out of the car, some places can test it on the bench. The regulator is built into the alternator and they are typically replaced as a unit. I would say there's about a 95% chance the problem is inside the alternator/regulator assembly. There are some people who work on the insides of alternators but most prefer to just swap it with a rebuilt one.
Recognized HCF Member
Joined: Sep 2007
Posts: 9,453
From: Houston, Texas
RE: Battery Light Warning
ORIGINAL: That1Guy
Ill give this a try. I was just Really trying to avoid taking out the alt as it sounds like it is quite hard.
Ill give this a try. I was just Really trying to avoid taking out the alt as it sounds like it is quite hard.
This is a good DIY project. Put the front end up safely on jack stands, block the rear tires, and then follow the steps in the picture. Definitely take off the lower mount bracket so that you are able to remove the alternator and put it back in from below the car.
Junior Member
Joined: Dec 2011
Posts: 3
The old alternator tested as dead at Autozone.
I put a new one in, at which point the red battery light came on continually.
1. I pulled the 4-wire connecter out of the alternator, and the light went off.
2. I tested the new alternator at Autozone (in the car).
3. I checked the battery fuse (the big one under the hood).
What else can I check?
I put a new one in, at which point the red battery light came on continually.
1. I pulled the 4-wire connecter out of the alternator, and the light went off.
2. I tested the new alternator at Autozone (in the car).
3. I checked the battery fuse (the big one under the hood).
What else can I check?
Recognized HCF Member
Joined: Jun 2007
Posts: 10,023
So you have more than 13.5 V at the battery with the engine running?(*) The alternator is charging then, but there is a problem with the light circuit in it. Alternator is defective, replace alternator again.
(*) That is all that the Autozone in the car test is. You can do it yourself with a voltmeter.
(*) That is all that the Autozone in the car test is. You can do it yourself with a voltmeter.
Recognized HCF Member
Joined: Sep 2007
Posts: 9,453
From: Houston, Texas
The old alternator tested as dead at Autozone.
I put a new one in, at which point the red battery light came on continually.
1. I pulled the 4-wire connecter out of the alternator, and the light went off.
2. I tested the new alternator at Autozone (in the car).
3. I checked the battery fuse (the big one under the hood).
What else can I check?
I put a new one in, at which point the red battery light came on continually.
1. I pulled the 4-wire connecter out of the alternator, and the light went off.
2. I tested the new alternator at Autozone (in the car).
3. I checked the battery fuse (the big one under the hood).
What else can I check?
