it happened on mine my guess is your alternator internal parts are dirty or the berring in the alternator is bad, these will still past alternator test try replacing it and see if the problem persist
In a 1997 Ford Crown Victoria : Fuse ( # 16 ) is a 20 amp fuse for the cigarette lighter
On a 2009 Ford Crown Victoria : In the fuse panel under the drivers side of the dash : ( check the # 16 / 20 amp fuse ) *** in the 2009 Ford Crown Victoria Owner Guide it shows the # 16 , 20 amp fuse for the OBD II , but the 2008 Ford Crown Victoria Owner Guide shows # 16 / 20 amp fuse for the cigar lighter and OBD II
fuse # 25 - 20 amp fuse
fuse # 16 - 20 amp - cigar lighter
# 16 is a 20 amp fuse for the cigar lighter
On a 2003 Ford Crown Victoria : ( fuse # 20 is a 20 amp fuse for the spot light ) In the fuse panel under the drivers side of the dash
On a 1999 Ford Crown Victoria : Fuse ( # 16 ) is a 20 amp fuse for the cigar lighter ( In the fuse box below and to the left of the steering wheel , by the brake pedal , it has a cover on it )
On a 2004 Ford Crown Victoria : In the fuse panel below and to the left of the steering wheel , by the brake pedal ( it has a cover on it ) ( fuse # 25 is a 20 amp fuse for the cigarette lighter )
# 25 is a 20 amp fuse for the cigarette lighter in a 2004 Ford Crown Victoria ( in the fuse panel below and to the left of the steering wheel , by the brake pedal )
On a 2008 Ford Crown Victoria : In the fuse panel below and to the left of the steering wheel , by the brake pedal : ( fuse # 16 is a 20 amp fuse for the cigarette lighter and OBD II )
On a 2000 Ford Crown Victoria : In the fuse panel below and to the left of the steering wheel , by the brake pedal ( it has a cover on it ) (fuse # 16 is a 20 amp fuse for the cigarette lighter and auxiliary power point )
( Fuse # 25 ) - 20 amp - cigar lighter , power point , emergency flashers