Boat won't start!

[justgary]

@formulaben is doing a great job here, so I kind of hate to chime in....

5 hours ago, ryan25duginski said:

No worries I don’t know enough about this stuff to get mad at your questions 

The first thing I tried was disconnecting the cable from the bus bar that leads to the rear of the bolt from the bus bar. When I tested for voltage there I got less than 1V but had continuity. This told me that something in the rear was sucking the power from the back of the boat to the bus bar

secondly, I tested for volts on what I believe to be the starter (again mechanically declines) I had less than 1V. 
from there I decided power wasn’t going through the isolator switch. So I disconnected the isolator switch, and ran the batteries straight to the motor instead of through the isolator. Upon doing this, I got 12.8V to the “starter?” I thought I had found the problem but nothing worked still. 
 

after that, leaving the isolator switch bypassed, I tested for continuity and volts at the bus bar again (remember I had volts though low, and continuity here before bypassing the isolator) only this time I had no continuity or volts to the cable end or just bar. 

In general, testing "continuity" with an Ohm meter should not be done with the circuit powered.  You won't get what you think you should get from the readings, and you can blow your meter.  You haven't said that that is what you are doing, but you have implied it several times.

From now on (unless we tell you to do differently), you are only allowed to put the black lead of your voltmeter on either the: 1) Battery negative post; 2) The engine block or a head, but only on an unpainted surface; or 3) The ground block under the dash.  When reporting voltages, you have to tell us where you put the black lead.

With the black lead on the battery negative post, tell us the following voltages by: 1) putting your meter on "DC Volts" and the 20 or Auto range, and 2) moving only the red lead to the various places.  You may have to figure out some sort of jumper cable situation in order to reach, but just be sure that your jumper cable is secure on the battery negative post and your meter's black lead.

Report these voltages (with the black lead on the battery negative post):

1) Battery positive post

2) Engine block unpainted surface, preferrably the ground point at the back of the head (OK, the "front" of the port head on your engine).  You should see several wires on a lug.

3) Starter big red wire

4) "B" terminal of key switch

5) Ground block under dash

6) Fuse block under dash (or maybe near the throttle)

Also, posting photos is good.  Don't be afraid to post photos and ask questions.

[ryan25duginski]

Got it. Again sorry, for the frustration and any confusion I’m causing. I’ll get all those numbers and report them. One battle I’m facing is that the slip is an hour from the house and I fight daylight, and a light only does so much. But I’ll get back to you with all of that. 
thanks 

[Team Newsom]

I spent SO much time and frustration last year troubleshooting and realized I missed the first and easiest step.  The ground on my battery was "connected" but not tight.  I have 3 batteries on a Perko and it's not the big negative post on my (typical) battery that was the issue.  I have small ground wires on a threaded battery post (connected with a wingnut).  These run back to provide the ground on my bus bar.  That saved me THIS year too as I needed to tighten them more after winter storage.   I chased all that other stuff and realized it was step #1 where I failed.  CHECK the battery connections!!

Edited June 13, 2020 by Team Newsom