I am posting this for my brother in law. I am not a mechanical wiz so please be patient. He has a Mercruiser 350 mag. This past weekend when he put his boat in the water it would not start due to dead battery. I jumped him with my boat and he drove to marina then shut it off. When he tried to start again it would not turn over. I tried to jump him again and it would not turn over. He then bought a new battery thinking the battery was the problem. While hooking up the battery he connected one of small wires that should have went to the neg post to the pos. Yes he had to force it on. Before he tried to start it he realized his mistake and switched it back. He then tried to start the boat and nothing, would not turn over. Checked lanyard kill switch and main breaker on motor seemed okay. We did find several small fuses that were blown. Replaced them and got blower to run but motor would still not turn over. What are we missing? Are there other breakers or fuses that we are missing? He seems to getting power just the motor will not turn over. Any ideas?
