Engine wiring Harness

[Ron Hill]

Kirk : When you cut the old connection OFF - strip some of the insulation off and the shine up the stripped wire before making a new connection!

A thought

[TortolaTim]

Kirk

If you are comfortable manufacturing a harness from scratch, when that time comes I can provide a list of everything you need and some sources. 

-kk

Ken, I'd be interested in that list when you get a chance. M25XP, Compass Marine Alternator/Balmar External regulator.
Thanks!

[KWKloeber]

Tim,

I can't attach an XLS file so I put it here.  See if this works.
https://c34.org/wiki/images/0/0f/2023.10.9_CTY_engine_harness_BUILD_LIST.xls

This is my generic STARTING point for a harness build -- it lists each typical terminal type and size and each wire length.  BUT I do them only with the old harness in hand because I've found differences in harnesses between years/boats and the length of each engine pigtail. 

Rather than try to anticipate questions just ask and we can take it from there.  I recommend only FTZ CNS (Crimp and Seal) terminals (NOT the "so-called better" Clear Seal.  The CS butts are better but not the other CS terminals. The CS are called "BEP" at Defender.

Some of my NOTES may be messed up -- I tend to forget to update my NOTES if I edit the wire into.
I make a 20' (nominal) harness, or 24" longer than OEM so there is plenty of slack if needed to work on the cockpit panel.

Caution: Lengths get customized based on how the new harness is routed.  On the C-30 it arrives from the port side engine compartment, which gets it the way to work on the engine, alternator, etc-- so I prefer running from aft, along a stringer.  How the owner runs the replacement affects the engine-end wire lengths because it's all in a split loom and one each exits where needed to hook up.  If you build your own it's not so much an issue because obviously, you can install it, figure out the length, and then install the HS terminal.   But most owners want a !00% drop-in and only a few have done their own engine end terminations.

Sometimes there's customization, like the last was a #8 for low V loss to a fuse block (to run from for a future high-power accessory); w/ the panel is jumpered from the fuse block.

I have no clue what the terminations are for your alternator/external regulation.  On the spreadsheet tabs I have a couple of the common Alts that Universal used.

ASK questions.

[TortolaTim]

Thanks Ken! That will save me a lot of work. I've "cleaned up" my harness and cluster wiring and everything works fine, but it was all re-done in non-marine wire ages ago by a previous owner. This will be a good project for me to tackle this winter as I'd like everything to be done right. I'll be sure to reach out if any questions come up.

[Ron Hill]

Guys : I say again -- that the wiring harness with the connectors was made for a production line.  You'll NEVER use those connectors again (unless you replace your engine instrument panel) 

A thought

[JoyRide2.0]

First off. Thanks for all the advice. My C34 is a 1991, so it has the three-way switch and a starter button. First off, I exchanged the switch with a new one... No Change. Dammit! Then, I changed the starter button with a waterproof one... BLAMB! Drop the mike. It was fixed. No more alarm. Then, I went back to the boat a couple of days later and my heart sunk. The alarm buzz was back. I guess there is a short in the old harness connecter after all. Doesn't matter I'm building a new harness, anyway. After all, it needs to be done.
Enjoy the weekend!

[Ron Hill]

Kirk : AGAIN - I'd just cut off the old connections and strip the wires, shine them up and connect them!!  I solder, others crimp- your boat your choice!!

A few thoughts