Reply To: 57 35hp – wiring questions please?

[John Gragg]

Okay,

So I setup sort of a bench testing of how these components work together. I have 50% of it figured out, I think.

Yes, the mercury switch appears to be in place to provide ground to the frame of the cutout switch so that when excessive vacuum builds up at low speeds there is a temporary cutout of cyl #2. I have tested it with a meter and it all does what it is supposed to do and the theory appears to be exactly what the book says.

Now, looking at the NYMARINE wiring diagram…

I attached a power supply to my brand new 4 pole starter solenoid. I put 12v+ to the large lug on the same side of the solenoid where the small pole has the “s” mark. I grounded the solenoid (to the mounting tabs) with the – side of the power supply. I then ran a (starter) switch wire from the same 12v+ pole and when I land that power wire to the “s” terminal I get power to the other large lug on the other side of the solenoid. Excellent, sort of… Here’s the kicker. I also get 12v power to the 2nd small terminal next to the “s” terminal. Not a huge deal, if this were an automobile. Cuz that terminal is meant to send 12v power to the coil. In this case, however, Peter’s drawing shows that 2nd terminal as being wired through the motor connector and somehow landing on the mercury switch? How can that be? Sending 12v power directly to a ground source results in sparky-spark, no?

Can anyone enlighten me on what the 411 is here on that one wire? It’s white on the boat side and turns black on the motor side. Supposedly goes to the mercury switch (On my motor I found it connected to the vacuum cutout switch). Either way, it has power during starting which will do bad things since both the mercury switch AND the cutout switch are negative reference, no?

Thanks!

John Gragg
RIverside, CA

Just starting in the hobby, please be patient.

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