I have a 93 cionvertible when I put heat or ac on seems to pop the fuse to the point that the fuse box is melting by kick panel any ideas and does a regular 240 fuse boe work if not where can I get one

Old fuse boxes with degraded/ aged/ corroded "socket" metal contact surfaces WILL do that , especially during prolonged HIGH CURRENT DRAW JUST UNDER AMP RATING . For a "short' or superhigh overcurrent situation simply IMMEDIATELY blows a fuse - doesn't give any time to do the meltdown act Any poor contact is what develops heat directly proportionate to AMPS & TIME.