My battery warning light keeps flashing on and off while I am driving (usually over 2500 rpm). My battery is still strong and the alternator gauge is always in the normal range. What is this indicator trying to tell me? I have a 98 F150 4.6V8 46000 miles

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I think when its flashing when the charging system is maxed out or something like that you mave have a loose belt or a bad pulley and when you hit 2500 RPM's making your warning light flash would be my best guess.

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2000 F150 XLT Reg. cab
4.6 Triton Engine
4x2 3.55 rear end gear
sliding rear window
automatic keyless entry
white styleside short box

 

Check belt condition and tension first.

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2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
4-wheel disc/ABS,Chestnut/Parchment,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification,Superchip,
Dynomax ultra-flow welded 3" cat-back.

 

My truck was doing the same thing but at 2300 rpms or above. The belt tension and pulleys were all good. I had the system tested at the dealership and it was the alternator going bad.

LeavenworthJeff
99 150 supercab XLT
4.6L 70,000 miles