Found something interesting while winterizing my PCM EX343 engine this morning...

[IDBoating]

I've done this for a few years now and am very familiar with the engine and engine compartment. I was pulling the knock sensors to let the block cooling water drain. On the left side of the engine (right/stbd side of the boat, since this is a v-drive) I remove the bolt and nut that suspend the transmission intercooler because it makes removing that side's knock sensor much easier, and because then I just disconnect the front hose on the intercooler to drain both the hose and the intercooler itself.

There are a couple fo wires and cables that string along under there. This time I noticed that one of them had a loose end that didn't go anywhere! It was a 6 gauge (heavy) red insulated cable in black split loom. The end of the cable was retracted in the loom several inches, and was cut very clean - straight across - not all ragged and such like you'd expect if it came off of something. This end had been resting just under the alternator.

Thinking that was darned weird, I followed the cable along. It routed around the back of the engine block (toward the front of the boat) and wrapped forward on the other side. Pulling on it, that end was free too! It had a nice 100 amp fusible link a few inches from the end, and the end itself had a very nice and professional crimp lug on it that looked like it might install on a 1/4 inch stud. This lug was completely wrapped in black electrical tape, which means this end was never connected to anything either.

So basically all this time my engine has had a nice 4-5 foot length of loom-protected 6 gauge cable wrapped around it, with a nice tape-wrapped lug on one end and a clean cut on the other end.

Any ideas? I'd be tempted to say it's support for an option I don't have, but it wasn't part of a harness or even tyrapped to anything. It was just fished through a few tight places and left hanging there.

[LKG PH Creek]

Perhaps it's for the not yet introduced Flux-Capacitor option...
Sorry, I couldn't help myself,

[chpthril]

Since Tige use a diode type battery isolator with its EIDB dual battery system, the main alt cable doesnt terminate at the starter. Rather, it goes to the center post of the diode Iso. That cable is likely PCM's engine harness, and Tige tucks that cable away in the loom and runs their own.

[IDBoating]

That cable is likely PCM's engine harness, and Tige tucks that cable away in the loom and runs their own.

Good call, I'm sure you're correct. I edited my post above, it's a 6 gauge cable and thus not meant to carry starting current. But it's definitely big enough to carry charging and operational current from the alternator.

Regarding your comment above:

the main alt cable doesnt terminate at the starter

...if the alternator cable terminated at the starter, how would it charge the battery? It would be on the wrong side of the starter solenoid and not connected to the battery most of the time. Are you saying the PCM alternator cable is normally connected to the battery side of the solenoid?

[chpthril]

Battery has to be connected to the starter, or engine no start. So alt output leaves alt, goes to starter main post and connects to the cable coming from the battery, Most marine engine manufacturers fallow this practice of having a short run from the alt to the started, then use the larger main battery/starter cable to send the alt output to the battery.

[Timmy!]

I was thinking it was a test harness from the engine mfr like chpthril said.