re-powering a 1995 boat, new 4 stroke merc to an old 8 pin harness

[katt68]

hi boaters,​

i am sure some of you have installed a newer motor to an old boat...​

so, my issue....​

i purchased the quicksilver harness assembly adapter to go from the new motor to the old boats 8pin connector plug...​

I have things connected but not starting so I am missing something.​

the starter will try to engage the flywheel but does not turn the motor over...​

from the adapter harness on the motor side...there are 4 wires outside the screw on plug...​

brown with white stripe...…………..for?​

tan...……… I think temp gauge​

the blue and green I have connected to the trim up and down which works.​

does this brown and white wire have to connect to something?​

on my old 8 pin plug side, there is a lone purple wire I am wondering where it may go...​

any ideas and help is appreciated...​

as I said, I am sure others have re-powered an old boat.​

darryl ​

 

[alldodge]

the starter will try to engage the flywheel but does not turn the motor over..

Have a corrosion issue, weak starter or motor has a problem

Brown/White = Trim sender to gauge
Tan = water temp sender

I would say with that kind of connector, the one in the pic may be brown and if so it goes to a Mercathode

 

[katt68]

connections and cables are all clean and good and tight...
I really suspect it is a wiring issue...
is there a safety wire or something I do not have connected that could cause this?

 

[alldodge]

Not normally with the 8 pin harness. The wiring is before they started adding a kill switch. Also a kill switch just kills power to the coil, the motor would still turn over

What motor and year was in the boat?