Emergency help needed, X5 wont start wont crank

[Roman D]

Hi guys, I really need some advice...
Bought another X5. Not a best buy so far - as-is, slightly tapped in the rear. Had it delivered as it was disclosed that it is non starter, not even a mileage reading. Connected the booster across tje battery - it went alive, buy wont start, i hear light click under the hood but not sure it is a bendix of the starter, no crank.. What I noticed so far, as I was trying to check fuses in the back, LED on the probe would lite up when i connected it across the battery (booster connected as well) but if. i connect brobe's power clips under the hood, there is a plus terminal, no LED for power on the probe.... There is a red wire that is finger thick goes to it, i assume, from battery, can it be broken? Any ides very welcome.. Thank you.