Most likely cause is a missed wire.. What I tell people who remove batteries is
1: Paint all positive leads RED (Optional paint negative black) These are TRADITIONAL not Standard colors. there is no standard.
2: Photo shoot
3: If multiple leads hooked to the same post (Except for battery to battery jumpers) TIE them together Or in your case BOLT them together. Insulate the positive Plastic something.. IE: Surgar Free Water flavor (Crystal Light is a brand name) and a wrap of tape or poke a couple holes and "Tie" it on)
YOu likely popped a breaker.