Can't find Wiring Diagram for '66 with 230 c.i. inline 6

[Jamespio]

I'm continuing to work my way through a '66 SabreCraft with a GM 6 cyl 230 c.i. attached to a Mercruiser sterndrive. This is identified as a model 150 or MCM 150 everywhere I look (for the nominal but almost certainly unealistic 150hp this engine allegedly produces). I have the Seloc manual and have searched online but cannot find the corret wiring diagram. Seloc has diagrams for models 120, 140, 160 and more but not a 150.

I'm fixing a LOT of bakcyard mechanic "shortcuts" and the wiring is much the worse for wear.
Also, my immediate need is to figure out the best place to find a power source for the brown wire that is supposed to go to the external voltage regulator, which in turn tells the alternator when to work. I actually found the original wire, cut short at both ends, but still in the harness. Seems easier to me to find an ignition dependent power source somewhere int he stern, like at the solenoid. Thoughts?

 

[makomark]

there are three separate diagrams for a MCM150...to segregate them, the answers to the following questions are needed:

1) is the voltage regulator a transistorized version or the (older) relay version?
2) is there a charge indicator light on the instrument panel?
3) how many wires (in total) connect to the voltage regulator?
4) is there an AMP meter on the instrument panel?

FWIW, NONE of the diagrams I have have a brown wire connecting to the voltage regulator...the ignition lead appears to provide excitation to the alternator and those are WHITE leads...the early style, with the indicator lamp on the dash board is an odd ball and in more than one way...

 

[Jamespio]

Yep, brown wire is not relevant here, that was a bad piece of info I picked up from the SBC community (well, a good piece of info for some SBCs, not so much for me).

I found a better diagram, and I think I solvd the problem, once I found a WHITE lead that terminated at the last row of tape on the harness. I put that back in the same circuit as the original white lead from the ignition, which also helped clear up some confusion I had while installing a new distributor over the winter. So with 12v goinginto the voltage reg I though i was good to go, but still wasn't getting voltage from the end of the wire going to the Field position on the alternator. As a last ditch I ditched the brand new voltage reg and tried the old one out, and I'm suddenly getting 12v on the Field excitor line, and when I plug it in, I almost immediately get 14.5 volts back out of the alternator.

I committed the sin of changing out too many pieces of hardware at the same time. And a brand new, but defective voltage reg got into the mix. Why does electrical gear for 50-year-old vehicles suck so bad?

 

[Jamespio]

Here is a shot of her from last summer.