Overzealous mistake: Heartbroken

[Jrennicke]

I am very new to boats (as you will soon learn) and made a really dumb mistake. I have a 2017 Yamaha 40 hp four stroke in my C-Dory with a two battery system. In my understandable excitement to get on the water and complete and utter ignorance, I hooked up the batteries incorrectly, fried the harness and apparently some electrical components in the engine itself. I am utterly heartbroken and sick about it. I did bring it in to a certified Yamaha shop and they are looking at it but I can't wait. I need to know how much damage I might have done. Can anyone give me some advice?

[fairdeal]

I'm saddened to hear the wiring harness is damaged;
sometimes, on some models,
one escapes such a mistake with only the main fuse blown.

Worst case, in damaged parts ?
I would guess

WIRE HARNESS ASSY 6BG-82590-04-00 $987

RECTIFIER & REGULATOR ASSY 6BG-81960-00-00 $215

ENGINE CONTROL UNIT ASSY 6BG-8591A-04-00 $732.

and then there is Labor...

[Jrennicke]

Thank you. Cheaper than a whole new engine.

[99yam40]

when you hooked them up wrong was it just getting Pos and neg wrong?
surely you did not hook the 2 batteries in series and put 24 volts into the system?
did it let the smoke out as soon as you hooked it up?
or did it wait until you tried to start the motor?

letting the smoke out of electrical stuff in never a good thing

[Jrennicke]

Unfortunately, the first one. It started to smoke RIGHT away and we unhooked it as quickly as we could. So I am guessing we did hook it up in a series and put 24 volts into the system.