'95 ECM-B fuse blowing! Need help!

[The Big Green]

Ok, it's a GMC '95 with a 305 but the vin showed a 4.3. I know the tranny was a 5spd but it's 4L60E now. Not sure it'll matter though. I had a coil pick up, and ignition module go out, then the fuel pump got weak and wouldn't run the injectors for the TBI engine so I replaced it. It's now blowing the ECM-B fuse, the mini fuse under the hood and that let's the fuel pump kick on. Now I replace that fuse, turn the key and POP, it blows right away. It's blown two. What's the deal? I suspect wires touching but beside the fuel pump what should I look for? What other things does this run that could be grounding out?
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[The Big Green]

It's just a fuse for the fuel pump relay. I'll have to check my fuel pump ground I guess. That's probably it lol. Just answering myself haha.
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[fixit-p]

This is the only diagram I have and it is pretty vague but if you are blowing a fuse it's due to over-current possibly from a short to ground, does it blow if you remove the relay?

[The Big Green]

I did some searching that's why I knew it was the fuel pump only. Yesterday I put the 3rd fuse and it blew when I turn the key on. It doesn't waste anytime at all. I can pull the relay and try again after work and see if it blows right away. Without the relay it won't work anyhow but it could be between the two. I know I lack a good ground.
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[fixit-p]

A poor ground wont blow a fuse, low resistance to ground will, either through the fuel pump or a dead short. Pulling the relay will just verify that the short is between the relay and fuel pump. Most likely when you put it all back together a wire was pinched causing a short.

[The Big Green]

Here's a little more info if it helps. My pump was bad, it's a blazer tank, and I have a '94 I use parts for my '95. I dropped the tank and pulled the '94 fuel pump but because it was a longer bracket and hit bottom of the blazer tank I pulled it apart and used the pump only. Now with a 1/4 tank it's showing full, well maxed out almost back around to empty. Now I have this fuse blowing, and I shouldn't have any wires touching. I pulled the bed, swapped pumps and it sounded good and worked fine for a while. The pumps grounded to the frame, because of the blazer tank the pump wires and plug was cut off and spliced from behind the cab to the rear.
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[The Big Green]

Ok, I got the rear of the bed raised enough I can see all the wires. Here's what I have. The fuel pump plug was tapped into and run the the rear. Just twisted wires and tape. I didn't see any bad spot from the cab back. The ground isn't the best, it was broke off the pump and twisted and taped up so it doesn't touch anything else. Theres a few wires that are cut and just hanging around. Two are at the rear, both purple and may be tag lights since there's no bumper or roll pan. Those are like 14-16g they are small. There's two more, one black and one orange, these are by the rear drivers tire. They are 8-10g or so, pretty big wires. Found a tape around then that reads (Orange=PWR-feed) (Black= DK AUX). I raised the bed in the rear messed with the wires making sure they are broke and grounding by the pump and turn the key on and the pump worked and the truck started. Hate to drive it to meet the guy I'm tradin and it break down, wouldn't look too good lol.

Just FYI: the guy knows all the little problems and I wouldn't trade if I was unsure what was wrong. It can't be a whole lot, its surely a easy fix if I can find the source of it.
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[The Big Green]

I appreciate the help but I'm pulling it to the shop tomorrow. Thought about doing a fuel pump because it could be a bad used fuel pump. When it works it's loud and sounds good but it may be causing the fuse to blow. I don't have the tools or knowledge to fix electrical stuff. I'm a shadetree type mechanic guy with no tools really lol.
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