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Control wiring harness

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Micksq

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I think I need to replace the wiring harness on my 1999 Johnson 50 HP ....from the key switch to the motor ... where do I acquire one? I have changed everything on the motor its self...power pack, stator..everything that has to do with the electric circuit...it still starts sometimes and runs great...then will not start at all....I have replaced the key switch....we live on Anna Maria Island Florida with high humidity...the only left is the wiring harness....or buy a Yamaha .....
Thank you all in advance
Mick
 
I think you need an OMC Factory Service manual and do some trouble shooting. Wiring harness are expensive if you can find them.
 
if the motor will not even turn over have you checked the neutral switch?if it turns over and will not start then disconnect the kill switch....that will be a green and black wire going to the power pack...there is a inline disconnect under the cowl for that...

once a motor is turn enough rpm's to fire(300 minimum) the only circuit that will stop it from firing is the above mentioned kill wire...it has to go to ground to kill the engine..either by activating the kill switch or cutting the ignition switch to off...

the circuit to turn the motor over is simply 12volts through the neutral switch and through the start switch to apply 12 volts to the pick coil on the starter solenoid.

i will be surprised if you have a wiring harness problem...but if you do it should be simple to find it with the simplicity of the circuits involved....
 
Papyson... I have done everything you suggested ..... spent $400.00 plus on a mechanic......sometimes spark and runs...then the next time out, nothing......has to be a short or something going to ground.......I have changed or tested every component except the harness...

The motor runs perfect once it is running....then a couple days later...nothing

Mick
 
if the motor is turning fast enough to start it then the only signal that can kill you that is harness related is the black/yellow wire going to the power pack...if the the key is turned to start or is turned to run that wire should be floating...it will be ground when the key is turned to off or the emergency lanyard is pulled..

i would put an inductive timing light in the boat and see if you are getting fire when it fails...the decision is whether it's a fuel or fire problem...
 
Papyson....I have been dealing with this issue for close to a year now and it has never been a fuel question....even the high cost techs that have operated on the unit agree that it is not a fuel problem.

Mick
 
Run a wire from the power pack to the ignition switch bypassing the yellow/black wire and see what happens. This should be for testing purposes only.
 
agree with that..thats the only wire that will kill him...a good place to tie in is at the inline disconnect om the black/yellow wire under the cowl..
have the techs ever saw a failure?a timing light would verify a fire problem...
 
often when a problem has been going on that long it is best to start from scratch....its always possible that there was or is two problems on the motor...its also possible that with all the activity and parts replacement that an additional problem has been introduced..
 
I will try the yellow/black wire again when I return to AMI Florida....I am presently in Sydney Australia and though I could have an answer when I returned home..... thank you all for the insight...I will report back after testing you advice.with results.
Hope to be fishing by Nov 6th
Come on down...red's will be running
Mick
 
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