My husband changed the battery and mistakenly connected the cables wrong way. While it was in that state, he cranked up the ignition, the engine didn't start. Realized his battery mistake, connected it the right way, the engine cranked up but wouldn't totally start anymore. He kept turning the key in the ignition, now there is really nothing happening to the engine. The dash lights are working, however we blown the fuses of the VHF radio and the stereo as well. The tilt wouldn't go up but would go down. After he kept turning the key in ignition, the tilt wouldn't go up and down anymore. Before this battery incident, everything was working properly with no problems whatsoever. A lot of people gave suggestions but I would really appreciate it on which is the best area to start first in checking or testing stuff and what could be wrong. I know it might be too much to ask but it would really help to point us to which parts or area of the boat to check first, second, third and so on and so forth. As for the steps of testing it, we have the engine manual to guide us but sometimes tips from all of you who had gone through the same process as ours would really greatly help.I'm sad about this mistake but I felt bad for my husband feeling so guilty that he made this mistake and kept saying sorry to me. Any help would be appreciated 
