Main fuse keeps popping
 

Hello everyone, this is my first post. I recently replaced the belts on my 95, v6, m/t, 4runner. I took the battery out to better get to the p/s belt. After replacing the belts, I didn't think and connected the neg. cable first. The battery arched and blew the 80amp main fuse. I got a new fuse and went to connect the battery the right way, but it still arched and blew the fuse immediately. No matter what I do it blows the fuse. No, I do not have the terminals mixed up, the ground is tight, and I do not see any burnt wires. I really appreciate any help, thank you in advance!!!!!