Alternator failed and was replaced. New alt is charging now, tested by mechanic to be fine, but upon deceleration at about 10MPH, charging light flashes on then back off. Does not happen all the time. Seems to coincide with down shift (automatic). All good except annoyance of light.

I changed the fuse but that didn't work. What else should I try?

Is there a schedule I should follow? At what milage should I replace the timimg belt & water pump? Is there any other maintenance I should be aware of. I have already replaced the serpentine belt & brake pads.