Mine did the same thing for 2 weeks (5,500RPM Shift Light) then it stayed on.
New Alternator and Belt installed.


99 SVT Black/Tan #1090/2760
82K Miles.......B&M Edge Shifter
Mobil1 5-30.....Side Markers
Ford Synth MTX # XT-M5-QS
Locking Lugs....Cup Holders
Black Sail Panels...TH Fix
Aluminum Gas Filler Door
BS Potenza S-03's
KVR Cross Drilled Rotors + Pads
Dual Mode Damper - soon
Clarion head unit
Pioneer 2-ways