X5 won't start after frontend crash

[InThePeg]

I'm hoping that someone may be able to help. I purchased a X5 after it was in an accident with front end damage. The car is now repaired but will not start. Originally I thought that I had an issue with the battery so I went out and purchased a new one and the starter still wouldn't turn over. What I found was that next to the positive terminal is a little black box and the power cable was loose. So I moved the two tabs and pushed the cable in. The starter now turns over however the engine won't start. I imagine that the fuel pump may be off. I have also heard that BMW sells a positive safety clamp repair kit and that this may need to be replaced after a collision occurs. As always the dealer will not tell me this rather say "bring the car in and we will look at it". Sure after I tow the truck at their mercy and end up selling my kidney to pay the final bill "No thanks!" Anyone know anything about this power cable and what type of circuit is inside that wire that would not turn on the fuel pump? Do I need to get this repair kit?

Any info would be greatly appreciated.