93 century stalls loses voltage

1993 century tries to stall and loses voltage meter drops way down. usually goes back to normal after a little while or when you reduce elec load by turning something off. does not have to be a heavy elec load for this to happen it has happened with or without the a/c radio lights on. have cleaned connectors at the starter battery and where they go into the firewall. also small pigtail from battery splits into two wires that seem to be fusable links? connector is getting hot where these fusible links? plug back into harness. happens at idle or when going, hot or cold any ideas please help

You might need a new or better alternator, just my thought's, might be wrong