Robertlatham1
New member
Hey guys new here. I have a 79 evinrude 85hp. It's been running great until I wired all my gauges solinoids motors lights ect... when wiring was done motor started and died never to start again. I lost all spark to all 4 cylinders. I started checking all the usual suspects cd4 stator timer base plugs coils wires ect..... went through CDI diagnostics procedure. Was certain it was stator and timer base. Low and behold I decided to look at ignition switch as this was the only part I had not looked at. I found the black/yellow wire (Kill circuit) at some time prior to my ownership of the boat had been put on the non raised M terminal and the black ground wire had been placed on the raised M terminal.
Sealed them around and bingo motor purrs like a cat.
Moral of the story?
The kill circuit black/yellow wire is an isolated circuit. DO NOT put normal grounds on black/yellow wires. You may think a ground is a ground but this is not true.
An isolated ground means exactly that. It is isolated from the rest of the electrical system grounds through the cd4 ignition module itself. Any continuity or induced voltages will cause the SCR in the CD4 module to not fire.
Sealed them around and bingo motor purrs like a cat.
Moral of the story?
The kill circuit black/yellow wire is an isolated circuit. DO NOT put normal grounds on black/yellow wires. You may think a ground is a ground but this is not true.
An isolated ground means exactly that. It is isolated from the rest of the electrical system grounds through the cd4 ignition module itself. Any continuity or induced voltages will cause the SCR in the CD4 module to not fire.