BF50 won’t start after power washing

I have a BF50 with fuel injection that I unwrapped this spring and started right up, no issues. After power washing the boat I noticed I no longer was getting the two beeps. After tiring the key 2-3 times the boat turned over and fired right up. I took for a lap and figured it would dry out with the upcoming sunny days. But it got worse. I haven’t been able to get it to beep or turn over since. When I turn the key my red and green lights flicker as if it’s shorting our somewhere. And if you listen closely can hear it trying to beep and do the lights. I disconnected the harness and dried both ends out thinking I had the issue under control but it’s still fighting me. Starting to think it could be the ignition key. Looking for any help. Thanks guys. Considering spending $300 on a control box to see if that solves it. Wasn’t sure if re wiring the control box for a new ignition switch is possible for a weekend mechanic.

I would not replace parts by assumption, it can get expensive. First of all, get a conventional test light (not and LED one),clip to a good ground on the engine block and then hold the test light on the positive pole of the starter relay and check whilst turning the key on and then crank position that the light doesn't dim. Another simpler way to check battery voltage is see if the motor trims up and down normally.After that check power to your fuses on the motor, again, with the test light, not a multimeter. Let me know what you find. It's highly unlikely the ignition switch would have water in it. Also , do you have a battery isolator? This can be affected by water too.

I agree with not throwing expensive parts at it. You have likely power washed a connection that wasn't a great one to begin with. Start with some basic checks and procedures.
First...take the battery cables off and, using a stainless wire brush or battery post tool, clean the posts and inside of the cable ends to a bright, metallic shine. Reconnect and try it.
It's best to think of electrical connections in this way; cleanliness is next to Godliness.
But washing them actually causes corrosion when they really need to be metal to metal. If the cable treatment doesn't work (did you wash the battery?) Take out each fuse and gently clean the ends and sockets with small pieces of scrub sponge or other non-metallic method. Steel wool isn't good as it flakes off metal strands and could cause a short. A product called De-Oxit is good for these small connections but it's a bit pricey. Old fashioned elbow grease is all you need.

Try some or all of these simple approaches because, whatever it is giving you a problem, it will turn out to be something simple caused by the powerwashing.

So the batter connections are fine and the trim on the motor works as well. I no longer have any signs of life in the controller. So I’ve disconnected the wiring harness and check to see if I have any power from any of the pins and there is nothing. I have checked the fuses and have power at the top 30a and the third slot with 10a and bottom 30a. Total of 7 fuses and 3 spares. Should I have power to all of the fuses under that little box? I was really hoping my light would light up at the 13 pin connection.
Wait, it looks like 14 wires. It appears a table has corroded away being the White with black wire. I just tested that from the motor and I DO HAVE POWER to just that one post. Should I have any more power than that? And what would be a good way to repair this without having to buy a new harness? Hard wire it?

"A table has corroded away". Could you clarify what that is? A cable? Meaning a wire?

You should have a Hot At All Times wire to the ignition switch. That may be the one you found.

That hot wire may branch off and feed a fuse or buss bar too.

Then, you will have fuses that would only get power with ignition switch in the ON position. That may explain why some fuses aren't powered.

Most harnesses can be spliced and repaired but if the wiring is "rotten" under the insulation, it might make more sense to replace it.

Without a proper wiring diagram you will just have to trace out the circuits for each function you should have. It's tedious but it's doable and you can make a diagram booklet to have for future troubleshooting. Not to mention the intimate knowledge you'll have of the boat systems when you're finished.

White with a black stripe is indeed the main power supply, the other fuses you refer to will e live once you have 12 running through your ignition switch and back to the motor.

“The table has corroded” table = Tab on the inside of the male plug of the harness. I was out at the boat and should have proof read my post. Sorry for the miss-spelling and poor grammar.
So 13 of the 14 wires will connect when plugged back together. I don’t want to have to replace the harness if I can get away with just plugging it back in and then using a wire crimp tap to create a jumper wire that goes around the plug. I think that should do it.

I made the jumper cable and the controls beeped and the boat fired right up. But then after idling for 50 seconds it shut off. When I turn the key now it beeps a rapid 4 and a late one.

The motor will turn over and run and then shut off and beep rapidly over a dozen times and then finishes with 2 beeps like it’s ready for me to start it again. Just when you think you’ve solved it some other issue I’ve never seen pokes it’s head up.

Sounds like your best bet is to replace the harness, if one terminal was corroded there has to be more with bad contacts.

Hard wired a the jumper cable over the plug. I was using a crimp wire tap before. Turn the key and two solid beeps. Started right up and I put it in gear and gave it some throttle and she was good to go. Thanks for the help. I’ll be back. As long as I’m a boater I will be at least.