Shortening Outboard Engine Wiring Harness, Battery Cables

Electrical and electronic topics for small boats
jimh
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Shortening Outboard Engine Wiring Harness, Battery Cables

Postby jimh » Sun Oct 02, 2016 10:03 am

In another thread a question was raised about shortening the pre-assembled electrical wiring harness of an outboard engine and its primary power battery cables.

Jefecinco wrote:On our SPORT 13 boat...[the existing remote throttle and shift cable and electrical wiring harness] are much too long. They are coiled in the rear of the boat behind and under the rear thwart....The wiring harness is probably something which can be shortened, but I believe it has perhaps a dozen individual wires. I assume each wire would need to be re-terminated and some careful soldering will be needed. The only cables in the bundle currently in use are the ignition and tilt and trim cables, as the boat has no gauges installed. A cable bundle exits the binnacle with each cable terminated with a heat-to-seal butt connector with a nice little rubber plug inserted into the unused end of the connector. I assume the bundle is intended to send engine operating information to a gauge set.

The battery cables from the engine are also too long, but even I can shorten and re-terminate them--though I lack the crimping tool for the large connector.


The outboard engine electrical harness assembly could be modified in the field. I discourage attempting to shorten the wiring by using butt splices. If you can obtain an exact replacement for the connectors at the helm end, and if you have the proper tools and experience with installation of those connectors, you could shorten the cable and re-install all new connectors. Modern cable assemblies generally do not use solder-cup connectors. Most modern connectors use crimp contacts which are then inserted into the connector body. Buying electrical connectors can be a very tedious project. Specifying connectors often requires very careful study of the manufacturer's literature, and often one has to buy all the individual components of the connector: the connector body, the insert pins or sockets, the strain relief, any boots or bushings, and so on. If your engine uses connectors made in Japan, this project can become extremely tedious.

The primary battery power cables to the engine from the battery can also be shortened. To install new ring terminal connectors you will probably need a hydraulically-operated crimping tool and die set. The bargain tool outlet Harbor Freight has a crimp tool kit for about $80 that can do this. You can also order pre-made cables of any conductor size and length, terminated with ring connectors from an on-line vendor like GENUINEDEALZ.COM. The cost of those new cables will probably be about the same or less than the cost of a crimping tool. See

http://www.genuinedealz.com/custom-cables/custom-battery-cable-assembly

Before embarking on this project, please recall an old variant of Murphy's Law:

Any cable cut to length will be too short