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Battery light issue

Today my 98 Expedition just started at 50 mph or 3000 rpm with battery light flickering and voltage fluctuation toward high end of 18 volts. Battery is 1 month old. No problems under 45 mph or 2500 rpm. Any ideas??

Sounds like the voltage regulator in the alternator has gone south. If you can verify the voltage is really that high with a reliable VOM, I’d change it before you burn out all of your light bulbs.

The alternator is bad alright. Change it out ASAP.

The battery light doesn’t tell you the condition of the battery, it is better to think of it as a charging system warning light.

Agree with the above posts regarding your alternator though.

Make mine a 4th vote for the voltage regulator in the alternator.

Actually GM had a problem with an intermittent connection on the ignition wires that went to the starter. They had some wires that connected to the battery cable post on the starter, and if they ran into an intermittent short, they would suddenly show a voltage jump that would max out the voltage gauge. I had this happen recently to me.

Sounds like a bad voltage regulator.

THANKS–getting checked/fixed today.