WHAT THE HECK.i got fire one min,and the next min i dont

[DLP321]

I have a 1978 Evinrude 150, with a short in the wiring from the motor to the key switch, problem is i cant find it, the motor will start sometimes, and other times it will not.The motor turns but no fire to the plugs. Is there a way i can test each wire cumming out of the key switch to the end of the big plug in the back. I replaced the key switch thinking that this was the problem. It wasn't.. please help ..... thanks Ps.
I had a boat motor mechanic test for a short and he said that it was between the motor and the key switch

 

[crb478]

Re: WHAT THE HECK.i got fire one min,and the next min i dont

You can cherck each wire for continuity with a multi meter or you can simply get a long wire and test each terminal at the key switch and then the motor checking them one at a time. When the problem goes away replace that wire in the harness. Look under the secret file for teh red plug wiring diagram.

 

[DLP321]

Re: WHAT THE HECK.i got fire one min,and the next min i dont

Thanks for responding to my problem; how I can get a copy of that diagram, I never herd of a secret file

 

[crb478]

Re: WHAT THE HECK.i got fire one min,and the next min i dont

look at the top of this forum for Johnson/evinrudes its there

 

[F_R]

Re: WHAT THE HECK.i got fire one min,and the next min i dont

The culprit wire would have to be the Black/yellow stripe one. That is the one that kills the ignition. Disconnect it at the engine end and if you then have fire, you found the reason. That wire carries a nominal 300 volts, so a multimeter check may be meaningless because the 300V will arc across a fault, whereas the low voltage of a multimeter won't.

 

[DLP321]

Re: WHAT THE HECK.i got fire one min,and the next min i dont

Thanks