blown fuses

I have a 1994 it has a problem withblowing the fuse for the ecm located under the hood in the fuse box. I have had the wiring harnesses checked and there was no problem found. I removed the computer from under the air box and the fuse was still blowing.the problem is very unpredicatble. I have not gone to the dealer as I am not perpared to let them charge me by the hour ,by the time they get done I may have to trade my kids in to pay them. Any help out there.