well i been gone a couple months then i come home and try to do some maint. on my boat and motor...i took both batteries out to charge them...and i ran new fuel hose/bulb from tank...tonight i drop the batteries in and i think i crossed them!! sparks flew.....the nav lights work...the bildge pump works..curtesy lights work.......the radio dont work and the most important thing....when i turn the key over usually the power to the fuel/battery gage would come on..now it doesnt..and doesnt turn over at all..what do you think i fried? and where do i start to look to troubleshoot? last time i did this i ended up replacing my electrical system 