Help with Charging system issue, battery light

[ScAndal]

OK Here is the scenario: (sorry for the novel)

2000 Explorer XLS
battery light when on last week. Battery level guage was slowly dropping over the week. Went into Checker and they tested alternator. Tested OK. Said it was probably battery of cables.

On the way home battery level dropped to the bottom and abs light came on. Pulled into driveway and it wouldn't restart.

Time to take a look.

The negative post on the battery was pretty bad shape (almost 100% covered in white) so I cut it off and cleaned it up. I also put the battery on the charger and charged it up enough to start it. Started it up and it appeared that the battery was actually charging. level went up and battery light turned off.

I thought I fixed it. cleaned up and shut the hood.

Next time I go to start it, battery light back on and battery gauge low.

I pull out the tester and i'm getting 12.5 volts across battery posts when truck is off. When the truck is running i'm getting 12 volts across the battery posts but 14.4 volts when I put the negative test probe on the body of the car.

Do you think I have a bad negative battery cable? Could be corroded from the inside?

ScAndal

 

[Verno]

I would check the other end of your Neg cable. ou can do a quick test of the alt by touching a screwdriver on back of alt where the bearing is, if it pulls the screwdriver like a magnet then the alt is charging. Double check all your connections too. Generally if battery holds a charge and alt is good the problem lies in cabling. 85% of time it is the negative cable.

 

[ScAndal]

Great advice Verno.

I want to check the negative cable but I can't see where it goes to. What is the path from the battery? straight to the alternator?

ScAndal

 

[ScAndal]

Thanks for the help. Went to Oreilleys and got a replacement alt. Installed and everything is cool!