Trouble with connecting old Yamaha harness and tach with new engine.

[wtrueba]

I bought the Yamaha harness adapter and I got a tack with the three switches. To connect a new 2006 4 stroke engine using the old harness. I set the switches as instructed but is not working right yet. The tach trim displays shows is all the way up and it flashes even when I trim the engine up or down. Also the adapter cable has 4 plugs 2 go to the Tach and 2 to the engine. I have now only connected one to the engine because the other one is the old engine green pair oil cable wich I don't have plug in. Is the green pair oil cable connected on the new engine somewhere? appreciate your help. Thanks

 

[rodbolt]

Re: Trouble with connecting old Yamaha harness and tach with new engine.

depending on the year of your trim and alarm harness between the tach and the engine and the part number of the tach it may require two seperate adapters. see why its always just as easy to buy the tach kit? which incidentally for some reason is cheaper than just the tach. new the tach,since o2, comes set for 4 stroke,12 pole and 2 wire sender.
make sure your switches are set for 2 wire trim sender,4stroke and 12 pole. unless the 4 stroke in question is below 50 HP then consult the tune up spec guide. the 05 rigging and marine tech guide has some good info on mixing nd matching tachs and harness´s.

 

[wtrueba]

Re: Trouble with connecting old Yamaha harness and tach with new engine.

Thanks, RB. The engine is a 250 HP. I bought the adapter you suggested me on a previous thread. The one that goes between the Tach and the harness. I set the switches 1 up, 2 down, 3 up for 4 stroke. Is this correct? I only have the trim sender cable conected at the engine. Should I connect also the oil alarm? Where does it connect at the engine? I only see one plug for the trim sender. Thanks

 

[rodbolt]

Re: Trouble with connecting old Yamaha harness and tach with new engine.

if your running a 16,000 dollar F250 motor why not buy new alarm and rigging harness´s ?
anyway I have no clue what year harness your attempting to adapt, since 95 the engine harness used square rigging, to adapt post 95 engines to pre 95 harness´s for trim,oil and alarm requires a round to square adapter.
in 04 or so the tach changed again and in 05 the engine harness changed. I am on vacation in Venezuela right now so you will have to find your own copy of the 05 marine tech guide and it contains about ALL the info your asking. the 01-04 tachs require an adapter to work with the 06 motors but the actual harness fits. you will just have to have one or more adapters depending on your original trim harness,tach, and actual year of the engine.
as your seeminly doing it yourself have you any idea how to test the alarm audio,visual and speed reduction stuff or do the PDI sheet?
yamaha is getting a bit sticky about them.
I have no clue as to up and down, the switches are labeled on and off.
like I say, run by any yamaha dealer and the information you seek is in the 05 marine technical guide.
and occasionally instead of placing the adapter at the tach end I have to use them on the engine endof the trim harness.