GMC Repair: Fuse Blowing, fuse holder, gmc pickup

Question
1990 GMC pickup with a 5.7L engine.

ECM/Ign. fuse keeps blowing before and after installing a new fuel pump and fuel filter.
Now have a 20A fuse in the 10A fuse holder. seems to be holding.
Any suggestions?

Answer
If the fuse is blowing there is a short in the circuit. Take a multi-meter set to ohms, and check the wires for resistance to ground on both sides of the fuse. If there is any resistance to ground, then there is a short present. If all else fails install a 10amp circuit breaker in to the slot and if starts clicking unplug components and/or connectors in the circuit until it stops clicking, and that should point you in the right direction.