I am repowering my boat that had a 7.4 mood 330 go with a carb 454 mag. The issue is that it seems everything(radio curry lights, etc.) on the boat (98 25 outlaw) runs through the engine wiring harness. Is there a wiring harness that I can buy to use with the new engine or am I going to have to mutilate the one I have to get everything to work? Has anyone else done this? I have the mercruiser book with wiring diagrams but don't want to destroy the mpi harness in the interest of selling it when the install is complete.

you are going from injection to carb ? geeze... thats should be esentially plug and play. all the high voltage stuff will be the same and the injection harness stays w/ the motor. the carb motor needs a wire to the coil from the ignition switch and thats about it...which is one of the wires that comes off the master plug in the back of the motor...

I have wired dozens of race cars and stuff with one wire distributors and mechanical or wet line gauges, but this thing has ecectrical senders for water temp oil pressure low oil pressure warning horn. Electric fuel pump the trim motor everything quits when the mpi harness is disconnected. I can rig it and make it work I was wanting to know if there was an engine harness I can plug in to make all that stuff work without re-wiring the entire boat.

hardin marine sells replacement harness very easy to install.

http://www.keitheickert.com/c-146-wiring-harnesses.aspx

All the power to the dash and front of the boat gets its power from the alt/batt through the fuse link on the starter, then up to the breaker on top of the engine then through the harness(larger red wire in the harness). That is why you lose power when you disconnect the harness. The ground and 12v+ power the rest of the boat through the harness

http://bpi.ebasicpower.com/c/ALL6I/

Heres a cheaper source

Thanks I think I have enough resources now to find an appropriate new harness and get it re wired. Will let you all know how if there any other speed bumps and how it turns out.

Does anyone have the wiring or know where I can get the wiring schematic for a 2001 25 outlaw, I have a ground problem in my switches any help would be appreciated. Thanks

The boat does not conduct electricity. There is a ground run from engine to dash. It is unhooked somewhere.

only half my switches work so I'm trying to find a schematic to see where all the jumpers are