Vehicle electrical problem

It is actually blowing the ignition main relay. After replacing relay three times, every time the car would run less than a block. It would start up and idle then when I jumped in took off it would blow another, I would replace and it would start up and repeat. I disconnected the 12v negative lead from terminal and installed a 12v test light between lead and terminal it lights up bright. So I began in i/p fuse box under dash. Removed all fuses and breakers with no results. Next I went to under hood fuse/relay box, and continued removing fuses/relays one by one, and again nothing. Super frustrating. So next day at it again. It wasn't until I had a few of the big main fuses removed at once did the light go nearly all the way out. Those fuses are#3, #4, #7. Which are headlamp, battery main 2, and battery main 1. With those three out the light dims dramatically, reinstall any one and back to bright on the test light. The light went even dimmer when #33 mini fuse is pulled. That one is ECM sense. Which tells me that those circuits must all run off same power supply. I am a local Mobile mechanic, but ill admit auto/electric is not my strong point. This is not a clients car tho. This is my wife's car! So my pride has definitely taken a blow. Let me add that no other fuses have blown that I know of. Just the #11 ignition main relay. Thanks so much!

Yes, I disconnected the negative battery cable, and between the cable end and negative terminal installed 12v test lamp. It lights up, demonstrating that 12v+ is being conducted through the grounded negative battery cable. Right? I also probed around on different positive wires and known hot at all time fuses under the hood. I did this with battery positive cable removed, and test light clamp on positive 12v+ terminal. Using the probe to test different positive circuits. They all light up the the test light. Demonstrating that the positive circuits being tested are grounded somewhere in the system. Short to ground. Right?

Unless I pull the #3 #4, #7 maxi fuses. Headlamp, battery main 2, and battery main 1.

The ignition main relay is #11 in the under hood fuse/relay box. Thank you for your patience.

Which method are you referring to as being incorrect? Are you referring to the test lamp between neg cable and post? Or probing the positive wires and fuses with 12v+to see which are grounding the current? I don't understand what's wrong with my methods. Lol

Okay, car was running but didn't seem to be charging battery correctly, brand new battery dead in like two hours of driving and an hour of sitting. That night after charging battery back up. My wife started it while I was looking underneath hood. I saw an arc down on the negative grounding stud on transmission bell housing. It was loose. Next morning tightened it up, jump started the car expecting that all problems were solved. Nope, got one block down the road and started blowing relay. Since it is getting better ground, something isn't agreeing. Something has to go, but when I swap in a new relay will start back up.