Question About Fluorescent Ballast Substitution
Many ballast can be connected to 1 or 2 lamps some different lengths. The wiring may be different than your original (colors) look at the picture on the front of the ballast if it only shows connections for 2 lamps it probably will not work with just 1 lamp. This ballast should work found on line 13$.  Fulham Fluorescent Electronic Ballast 120V for for (1-2) F32T8 (2) F25T8, F32T8, F25T12, F30T12, F3... by Fulham