No Electrical At All

[mckagen]

pair of '87 150s - yes 1987. twin batteries appeared to be dead - havent used the boat in quite a while. trim motors worked just enough to trailer to the house. put batteries on charger. didn't seem to help. tried hooking up jumper cables to car battery (made stupid mistake - looked at +/- on one battery and hooked cables to other battery, which was in transom facing opposite direction. so hooked up +/- bass ackwards). bought new batteries. hooked everything up and now have no power ANYWHERE. no bilge pumps, no running lights, no CLICK when turning the key. Running jumper cables direct to starter turns the engine, but with no ignition, it obviously won't start. What would kill the power to ALL electric items on the boat? will the kill switch kill all the bilge pumps, running lights, etc?

[marcortez]

You popped a diode in the alternator.

[darcy45]

Ya i think the same that you must have popped a diode in the alternator.Just check it once.

[99yam40]

pair of '87 150s - yes 1987. twin batteries appeared to be dead - havent used the boat in quite a while. trim motors worked just enough to trailer to the house. put batteries on charger. didn't seem to help. tried hooking up jumper cables to car battery (made stupid mistake - looked at +/- on one battery and hooked cables to other battery, which was in transom facing opposite direction. so hooked up +/- bass ackwards). bought new batteries. hooked everything up and now have no power ANYWHERE. no bilge pumps, no running lights, no CLICK when turning the key. Running jumper cables direct to starter turns the engine, but with no ignition, it obviously won't start. What would kill the power to ALL electric items on the boat? will the kill switch kill all the bilge pumps, running lights, etc?

Look for blown fuses and hope you did not fry other electronics