I just finished most of the work with swapping my 496ho to the 500 efi. I have a couple of problems. there is a few harness that do not connect. the trim on the drive will go down but not up and the gauge for the trim is inop. there are two dark grey or blackish wires with single connectors that comes from the transome with no home. also there is a plug with a purple and blue wire with no home. the purple wire has power when you push up on the drive trim, so I think its got to connect to the pump some how. anyway any info or wiring diagrams would be great. And by the way does anyone know if the 500 efi must have water jacketed tailpipes so that the engine doesnt suck in water or can i use manifolds with short risers. thanks a lot John

purple and blue are the trim, go to the pump, wires coming from the transom are the trim limit and sender wires, should be 4 wires all together for each drive, though they should come out in pairs like speaker wire. if you look up the trim wiring in a manual, you should be able to figure it out as trim wiring is fairly universal providing somebody hasnt butchered it in the past.

hello i see you did this swap im about to start mine any advise you can spare would be great