Previously, we have noted that Mr. Lehman has been reluctant to start. The starter solenoid is a little rustball, and perhaps is on its last legs. For some history, see Mysteries, Cleaning and Watching.
Today, the starter didn't work.
Now we have time to do some diagnostics.
Previously, we could push the starter button a few times and eventually, the solenoid would click and away we'd go.
Today, nothing. When I listened in the engine room (other than the alarm buzzer) nothing. No click from the solenoid. Nothing from the starter, but that's not surprising if the solenoid's not sending juice to the starter.

Okay.
That means it's time to actually wrestle the old solenoid out from its awkward position between the starter, a cooling hose and the air filter housing.
Two hours later, it's out. Seriously. Two hours to remove two awkwardly placed screws.
I replaced the two wires from solenoid to starter. The positive feed wire was falling apart. That may have been the original root cause problem. But. Maybe not.

Drop in the spare solenoid that was in a box under the bed, and we should be ready to go, right?
Diagnosis Round Two
Nothing.
When CA pushes the starter button, my digital multi meter shows voltage flowing into the contact for the relay. It must be properly grounded, or there'd be no voltage.
No noise. No click.
And nothing from the starter itself. Not surprising, if the solenoid doesn't work.
Maybe what we're seeing is a problem in the starter button. This is a dumb idea, but I'm getting desperate. The meter shows voltage, but it seems to show a lowish voltage (10-11) not the proper voltage (12-13) in the starting bank.
The sun's out. The thing is charging. The solar array is pumping out 14+ volts; the batteries are getting full. A faulty switch is a dumb idea born of desperation.
So I made a mess of the starter switch wrenching it out of the binnacle in the vain hope that the switch has a poor connection. Very vain — there's no way it's the switch. We see voltage at the starter. It seemed low, but it was voltage.
Some probing with the meter shows that the switch may be flaky. The meter shows that it's unreliable at making a circuit. But it's not like it's putting out only 10V instead of 12V. It's a switch. All or nothing.
I think I tried using jumper wires to across the switch. I think it didn't make any solenoid click down below. I'm not 100% sure I did this properly, though. I may have merely touched wires that weren't really part of the switch circuit. I was desparate. I need to try that part again.
Diagnosis Round Three
I put some jumpers on the old rustball solenoid to see if it works. This was a simple setup on the workbench. I opened the panel to get 12V and ground. I wired up the solenoid directly to a breaker on the panel.
It worked. Zapped it with 12V DC and it clicked. Loudly.
Unpleasant. That means that it may have worked all along and something else was wrong. Like the positive feed wire's ring terminal had fallen off. Except that would have click but no start. I'm didn't hear a click.
So I take the new solenoid back out of the engine. Awkward job that it is.
I set it up on the workbench. I zap it with 12V DC and it clicks quietly. But it clicks.
So I put the probes across the two main Single-Pole-Single-Throw contacts. It appears that there is no useful connection in this solenoid when it's energized.
New In Box. Apparently Dead. What are the odds of that?
[I checked it again while writing this. It really does click quietly but there's no connection.]
Round Four
I put the old solenoid back in. It had worked when I bench tested it. I could make it click. And the resistance across the SPST switch drops from almost infinity to 6Ω more or less: current should flow.
When I reconnected the meter down at the engine and had CA hit the starter button, I saw 12+V flowing through the solenoid. But it did essentially nothing. No click from the solenoid when mounted on the engine.
How can there be no click when mounted on the engine, but a click when sitting on the workbench?
Broken connection? Grounding? No. Current flowed to the stud on the top of the solenoid.
Low voltage? Not really, my last reading was certainly 12+ V. The wire runs are short: 12' or so from engine to binnacle and back. I can't explain the 10+V I saw earlier.
Then the sun went down.
Gloom
We have our binnacle torn apart with a starter switch sort of hanging out under the instruments. I made a mess of the old switch getting it out of the binnacle: it has to be replaced. I also scratched up the binnacle. Sigh.
Since we see 12V at the engine, the switch seems unlikely to be the culprit. But it has to be replaced anyway.
The engine is back together with the old solenoid in place. It may work. It may not. It worked on the bench. But it's not working now. But maybe it's the switch.
Tomorrow: switch and solenoids. I can try another plastic Standard SS-581. It may be easier to track down at an auto parts store in the greater Miami area. I'd prefer to get a Cole Hersee M202 which is the original equipment. I may order one from American Diesel in Kilmarnock tomorrow just to have yet another backup.
We're anchored about a mile from the marina. A mooring ball came available this morning. We really want to move Red Ranger in closer to shore.
But if Mr. Lehman won't start, there's not much we can do.
I'm not desperate enough to short around the solenoid with two screwdrivers and force the engine to start that way. Not yet, anyway.
We're paying for the mooring and not using it. But. It's warm and we can get to shore. It's just a loooong dinghy ride.