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Jim, as you know I rewired the engine on my boat. I had it all in place and the new wiring with the new gauges in the panel were "dead" Finally I looked closer at the original wire harness. The wires insulation was fused/melted. Finally I just ran ground from the engine panel. I used #8 marine cable for the hot and ground to/from the panel. I also wired the glow coil power so it did not go through the key switch. (20 amps)

before;


Original wiring dia.


After, see the yellow wire does not go through the key switch and right to the glow coil push button. The right end of the termblock is where the new ground wire would be but wasn't on yet in this photo.


These were bad.. worse conductivity then they looked. the PO had actually cut the ammeter and glow coil wires and ran new ones but I replaced those too. The old wire harness is the demon in most of this Jim. The reason is; ALL the amperage from the alternator ran through a #10 wire!
 

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And, once committed to doing it.. I really was not rocket science and quite easy other then the difficulty of working in the sun heated boat in in late May and early June. My YC gets sun all day and we bake in it!
 

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Mark.. but what most of us keep not getting in our thick heads is the original universal engine wiring harness had an ammeter that took all the amperage through the #10 wire, It would heat up when charging demands were high. eliminating the ammeter, feeding the panel with new wiring + & - and taking cable directly from start battery to the starter (per mainsail) is the solution.
 

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The main starter current doesn't go through the ammeter, it is wired (almost) directly to the starter via the 1-2-both switch.

I think what MaineSail was proposing that you are referring to was to take the 1-2-both switch out of the starter circuit.

The things that go through the ammeter that are significant to this fault (as designed by Universal) are the glow plugs, the alternator charging voltage, and the starter solenoid.

If the starter solenoid is clicking, that eliminates the trailer connector as the problem, as the only things that matter when cranking are the starter solenoid voltage, which we now is OK because the solenoid clicks, and the voltage to the main windings for the starter, which are wired directly to the battery (or almost directly, the 1-2-both switch is inline).
thought I said all that :D
 

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Hi Jim! ltns!

Well it is true a diesel doesn't need electric to run. it takes some to start it unless, you have Paul Bunyan aboard to crank it :D

Jim if can you just find the glow coil and starter wiring and take a new wire from the batteries to the push button, the starter solenoid I think is 10 amps 2 glow coils 20 or so. Why we ran #8 wire. all the gauges and other things don't draw much at all. if you have a newer alternator, (self exciting) (self amazed me) you don't even need a wire from the panel to that either.

When it was all done.. is when I found out a NEW ground was needed too! #8 again :)

Good luck Jim!
 
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Every time the engine starts means you will be less likely to rewire the mess that is called engine wiring Jim! ( put it if off for 3 or 4 years) glad I did it though!
 
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