Fix one thing, break another

Last weekend I got towed in because the boat ran out of fuel. It ran out of fuel because the fuel gauge was broken and permanently showing empty. I think this is because of some electrical that got messed up after a new battery bank was installed through the same area. I added fuel, bled the lines and broke the nut for bleeding out on top of the second fuel filter.  

Need to plug the hole with the bleed screw  

Brown bleed screw spun too loose/open  

Radiator bleeder screw is roughly the same

So I went to the auto store because that's all that's open on a weekday night. Bought the only one in stock, went back to the boat and installed it and it broke the same way immediately. I realized I was spinning it the wrong way. What looks and in theory seems to be "tightening or closing" it is actually opening it too far. 

lesson learned and I went to 3 more stores until I found the same size part. Works now. Oh, and somehow the fuel gauge does too. 

I'm going to need to diagnose, test and probably just replace the fuel sending unit wire.