89 GMC C1500 E.C.M Fuse blows

Truck will blow 10 amp ecm-ign fuse every 5-9days and no starts until fuse is replaced.

I replaced the E.C.M, Now the truck idles high. I hooked up the scanner to it and it reads no communication. I have put 2 comps in this truck and it still reads the same thing. I checked the IAC also it's fine..