[knl25]

I just replaced both battery and alternator (Remy New from Advanced Auto) on my 2000 windstar. The car starts fine, but about 15 seconds after the engine started, the charging system indicator (the one with a battery sign) comes up. I need help on diagnosing this. One thing I should mention was that I forgot to disconnect the battery when I disconnected the alternator and there was a spark when the alternator wire touched the engine block. I don't know if this burned out any fuses or relays that are related to the charging system, and if so which one should I check?
Thanks!