annoying battery issue

[3.0ranger1227]

Battery light is on, gauge is showing low. When running a voltmeter across the battery terminals reads 11.5v. When turned off, meter across terminals reads 12.0v, and a meter from the positive terminal to the radiator reads 12.5v. What is going on? Replaced the battery terminals because both were toast. With the truck idling I cranked the volume, cranked the bass, and when the bass hit i flipped on all my lights. Truck didn't miss a beat. Gauge doesn't move at all when driving or when I hit everything like that.

 

[Muscleford]

I believe the volt meter should show 13.5 volts when the engine is running. Something seems a miss

 

[3.0ranger1227]

Autozone's battery tester showed a good battery that was a little low. Also showed a possible bad alternator. They want me to take it off and bring it in for a bench test.

 

[COPPERHEAD85]

As close to 14 volts as you can get with the engine running.

 

[Sasquatch_Ryda]

You need an alternator. That is why the battery light is on.

 

[3.0ranger1227]

You need an alternator. That is why the battery light is on.

Awesome.