So, a week ago my buddy was hooking up his second battery in the trunk, odyssey g31, had everything ran and fused in both front and back runs of 1/0, put the fuses in and went to start his car. And relays started tripping. He hadn't grounded the back batt apparently and so he took it to a shop, said ecm was fried. Was it possible the ground not connected to the back that could have blown it?
