blowing ecm fuses only in reverse

i'll try to make this brief, 5 times now, when i put my truck in reverse and give it a shot of gas, the ecm fuse blows, i change the fuse, and away i go. If i ease the throttle, it's fine. No problems in drive, even if i tramp on it. The last time it did it, i replaced the fuse, but it popped 3 fuses in a row as soon as i turned the ignition on. 2 days later it worked again, drove it 30 feet, put it in reverse, POP, dead again, brown wire under the hood getting hot, if i disconnect it, no pop, but no start. i have a gas can and a match, is this the solution? Please help my poor burbie
here are my specs:
1990 suburban 4x4, 350, tbi, 700r4, ex-us military truck, military & cop-car upgrade package, 170,000 miles

Howdy: Looked in my old '88 blazer manual. I'm going to list the units that are powered by that fuse. They may or may not apply to your '90 Sub. 1. stop/tcc sw, 2. EVRV, 3. ESC, 4. EGR, 5. Air Switch, 6. ECM.

Good Luck...........Steve

well, after $232 it works again, i would have fixed it myself but it's -20 outside and i don't feel like freezing, so i took it in to an auto electrician and discovered a grounded wire under the hood that made contact with my tranny dip stick every time i was in reverse due to the engine twist. Thanks for the help anyways