Also check that brake lights arenít stuck on. May sound like a dumb suggestion, but people have missed noticing brake lights being stuck on, especially in day time. If brake light switch gets out of adjustment, brake lights will stay on even with ign. switch off.
Spark when reconnecting battery isnít meaningful by itself - thatís normal because some things are on briefly when power is first applied (also, some years sound the horn for a fraction of a second when battery connected). Be aware that certain of the computers may turn on and stay on for several minutes after ign. switch is turned off (FSM mentions that - may vary by year). That can make it difficult troubleshooting a battery drain problem.
'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs