help no start
 

02 jeep GC 4.7 now this thing always starts no question. I have noticed a few days ago it wouldn't start because of bad battery connections. I noticed 2 black 8 gauge wires that come right out of the negative battery post cable those were loose. I took them off then 're put them on tight. Now car crancks fine but won't start. Wth? Could I have done? I didn't mess with anything but the 2 smallers wires that go to battery.