92 Regal blown fuel/ECM 20 amp fuse

I have a 92 Buick Regal Limited 3.8L engine with 199,685 miles on it. Recently I've been having a problem with my fuel/ECM fuse blowing. The first time it happened I put a new fuel relay in but that did not change the fuse problem. I put a new fuse in and after about 3 starts it blows again.

Last week the car wouldn't start. Figured out that my fuel pump went out so I replaced that and figured it would fix the fuse problem, but after 3 starts the fuse blew again.

Also, in an older post someone had this same problem and replaced there oil pressure sending unit. If changing this would solve my problem, how does the oil pressure sending unit relate to a fuel problem?

Would replacing the fuel filter do anything?

Any help/suggestions would be greatly appreciated.

Through researching I figured out that the oil pressure switch and the relay are wired to the fuel/ECM fuse, so that makes sense now. So if the oil pressure switch is my problem, how should I go about checking/replacing the part? Thanks again