I just had the battery idiot-light pop on the other day. It stayed solid, even though my voltmeter indicated normal! About 30 km later, the light started blinking on and off! When I got home, voltage checks indicated a fully charged battery, 14.4v when running, and all seems well. Just that idiot-light staying on! I finally popped over to my mechanic's & he basically came to the same conclusion; its fine! All connectors & wiring were traced and cleaned. Is there a relay, or something that can be the issue? The mechanic knew which wires feed it under the hood, but wasn't sure of anything further! Thanks!
Jim

 

It's possibly the alternator. I just had the same thing happen to my truck and I just had to replace the alternator. Take it to an auto parts store and ask them to hook their tester. This will tell possibly what it is.

 

regulator in the alternator is bad or is going bad.

it is actually the gauge that is the "idiot light". the battery light itself is what shows there is a problem.