Can a loose ground wire at battery cause truck not to start on 1994 Mazda B2300

My truck is having intermittent starting issues and i found the black wire from the frma to the neg battery post loose..theres also three other black wires at the terminal and the main one...could this cause the truck to not kick over or the fuel pump relay, inertia switch, or other things to not work?

Asked by for the 1994 Mazda B2300
Yes, you got it right..