So my ecm fuse keeps blowing. I tried and tried to figure it out with no luck. Now I have discovered that if I unplug the main relay the fuse doesn't blow. Where do I go from there?

 

The first thing to do is to get a schematic of the electrical system concerning the ECM.
Then look at schematic and figure out where power comes in and goes to ground.
A schematic which shows location of the wiring in the vehicle would also help

Without those things, you are left with visual inspect of the wiring looms
Look for wiring that goes near AC pipes or exhaust or just rubs against metal parts
Also, look for where water might intrude upon the electrical system ... green crusties/corrosion