Engine wiring question....what is this?

[mrybas]

What is this little barrel shaped thing that connects the red/yellow wires to the purple wires?

[a64pilot]

Resistor?
Then it looks also like a diode in line too

[rwidman]

It looks like a previous owner did something he should not have. That's certainly not factory wiring.

Yes, there is a diode. That is really puzzling. The other "thing" might be a choke or might be a capacitor. Look for markings on it and post those.

Better yet, find out how the boat is supposed to be wired and wire it that way.

edit: after closer look, the cable on the bottom seems to be a piece of shielded cable that might be part of an antenna system. Maybe you need an experienced electrical person to look at it in person to figure it out.

Can you contact the previous owner and ask him?

[hellosailor]

It is a disturbance in the Force.

And proof that a PO owned big floppy sneakers and a fright wig.

Without knowing what it connects? I'd guess it is a capacitor or diode wired in to prevent spikes or make a ground connection or some other admirable goal. Except, wiring a component up that way, on the fly and unsupported, the leads at each end will be work-hardened and eventually break off.

So you really need to find out where those wires go, and what was being attempted. Either it is not necessary/proper, or it needs to be redone properly, with support.

[skipmac]

The small black thing on the bottom definitely looks like a diode. No telling what the larger thing is on top.

First thing I would do would be to track the wires in both directions to see where they go and what they connect.

[Jubilee39]

Is there an aftermarket alternator. Maybe some sort of ckt for the idiot light

[Outlaw7]

Whatever it is, it is between switched ignition (ABYC Purple Ignition Switch to Coil & Electrical Instruments and Instrument Feed, Distribution Panel, Electrical Instruments) and the start circuit solenoid (again per ABYC red and yellow.)
I would bet it goes between a warning light and the starter solenoid to indicate if the starter solenoid stays engaged. I will bet he cooked a starter because of this once.

[four winds]

It does appear to be a diode and capacitor in series.

Based on proximity to engine and the other wires nearby, I'd guess it might be associated with the alternator.

It only allows current flow in one direction and maybe smooths or moderates the changes in that current.

Smooths out a erratic tach needle?

Prevents noise on the VHF?.

I don't know. But it ain't factory. And I do love a mystery.

[four winds]

Originally Posted by Outlaw7

Whatever it is, it is between switched ignition (ABYC Purple Ignition Switch to Coil & Electrical Instruments and Instrument Feed, Distribution Panel, Electrical Instruments) and the start circuit solenoid (again per ABYC red and yellow.)
I would bet it goes between a warning light and the starter solenoid to indicate if the starter solenoid stays engaged. I will bet he cooked a starter because of this once.

This sounds good. Notice the yellow/red is folded at the cap. So it's a branch circuit, paralleled off to something.

[Outlaw7]

Look again fourwinds it is a yellow red wire a alternator field wire is straight yellow. Brown is the color for a charge light. It is one of the obstacles that kept the black wire as ground for so long.

[rwidman]

Originally Posted by four winds

It does appear to be a diode and capacitor in series............

Or a choke. But why would it be connected between two standard wires and a piece of shielded cable?

Only the person who installed it could explain why it's there or what it's supposed to do.

One thing for sure - whoever did this did not use good wiring practices or technique so there's no reason to believe that it is accomplishing anything.

[mrybas]

The yellow red is the ignition switch and receives power when the key is turned to the on position. The purple wire goes to the alternator

[rwidman]

We cannot tell where the wires go based on the color of the insulation. We should be able to do this but there's no guarantee that the manufacturer or any previous owner followed the ABYC wiring code. Especially someone who would install something like we see here.

[mrybas]

Originally Posted by rwidman

We cannot tell where the wires go based on the color of the insulation. We should be able to do this but there's no guarantee that the manufacturer or any previous owner followed the ABYC wiring code. Especially someone who would install something like we see here.

I followed the wires, that is where they go. Yellow/red receives power when key is switched to the on position and the purple goes to the alternator.

[rwidman]

Originally Posted by mrybas

I followed the wires, that is where they go. Yellow/red receives power when key is switched to the on position and the purple goes to the alternator.

Well that's great. You have this uninsulated "mystery circuit" hanging in space next to the grounded engine block and it's connected to a live circuit.

So how about the OP? Can you contact him or is he dead?