Changed the batteries and performed the steps in the manual to synchronize, nothing happens. Any suggestions??

Batt. & contacts good, checked auto batt. dead? it was when I parked it 2 weeks ago/ Charged the batt. hooked it back up, I get the lights flashing and a sizzling sound from somewhere. Engine cranked once and drained the battery? help!! had to disconnect batt to stop whatever was sizzling