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New Engine Replacement: I have extra wires...

Posted: Thu Mar 09, 2017 8:49 pm
by Jim_D
All;

We bought new Yamaha 9.9s to put in our boat and they were installed yesterday. And like most things, two steps forward and one step back! The installer sent me a note--he had an issue on the install. There was a wire from the old wiring harness that connected to 20am fuses in each engine well. I put in pictures of the starboard and port engine wells. The starboard side still had the wire (port side was taken out by the installer). The installer was uncomfortable making changes to the new wiring harness; he thought it would void the engine warranty. I contacted the previous owner, and that was an install from the factory. So my questions:

1. What is the purpose of the wires and connection to the 20amp fuse? If I was guessing, I assume that this is to provide power from the engine rectifier to charge the house batteries? I

2. Where does the wire originate? Is this from the engine or was it fused to the wiring harness and then to the 20 amp fuse?

And then how the heck do I get this right? More a rhetorical question there. Unfortunately I did not take a 'before' picture; a lesson I should have learned by now!! So trying to reconstruct what right looks like. Anyone have a wiring diagram?

Thanks;
Jim

Re: New Engine Replacement: I have extra wires...

Posted: Thu Mar 09, 2017 10:50 pm
by thinwater
The charging is now through the harness and the red wire is not used (I was the installer on these). They charge just fine, though it is now only 10 amps at full throttle each, which basically doesn't do much at cruising throttle. I suppose that is why it can now run through the harness.

I guess the installer didn't read the manual.

Re: New Engine Replacement: I have extra wires...

Posted: Fri Mar 10, 2017 12:37 pm
by Jim_D
Awesome--thanks for the quick reply!
Jim

Re: New Engine Replacement: I have extra wires...

Posted: Fri Mar 10, 2017 9:31 pm
by thinwater
Glad I could help. I had the same issues when I swapped engines a few years ago. New engines are so nice.

BTW, I'm in Deale too, just across from the fuel dock. Since you are local, you might find some interesting stuff in my blogs:

http://sail-delmarva.blogspot.com/
http://theotherchesapeake.blogspot.com/

Re: New Engine Replacement: I have extra wires...

Posted: Wed Mar 15, 2017 8:04 am
by Jim_D
Found them and they have already been a big help. What drove me to replace the engines was repeated work on the engines, and your blog on lifting the engines was extremely helpful! We keep our boat at Herrington Harbor North; on the hard right now waiting for a weather window to get some new paint on the bottom, then taking her around the Great Loop starting in May...

Jim

Re: New Engine Replacement: I have extra wires...

Posted: Sat Apr 01, 2017 7:49 am
by Phenix-former-owner
Good info. I'm replacing both engines next week! They arrive next week, I'm excited. What I have coming out of the old engines (1995 originals) is (see pic):

- 7-pin male harness (which SIM Yamaha says they will duplicate on the new engines)
- cable to battery (positive and negative)
- red wire and black wire (going ???). I snipped them.

Unlike the original poster, the black and red wires do not go to a breaker or fuse in the engine well. I wonder if these are the alternator leads for battery charging. I'm sure the new engines will come with some documentation.

-

Re: New Engine Replacement: I have extra wires...

Posted: Tue Apr 04, 2017 10:39 pm
by amytom
The new engines, and some of the old ones, will charge through the main battery cables. Take the cover off the engine and trace the wires from the rectifier to the junction block at the same point as the battery cable.
They really make this easy.