Outboard Engine Wiring to Tachometer

Electrical and electronic topics for small boats
STANZURAY
Posts: 1
Joined: Tue May 07, 2024 1:51 pm

Outboard Engine Wiring to Tachometer

Postby STANZURAY » Tue May 07, 2024 2:03 pm

[I am] putting [what is inferred to be a Yamaha] F70LA outboard engine on my boat. I have everything done but the initial wiring to the tachometer [shown in Figure 1 and is presumed to have the part number shown on the box also in that image, which is 6Y8-8350T-21-00] and to the remote control. I have the main harness installed.

I live in a small village on the Yukon River, and I cannot bring the motor and boat to the dealer. I cannot figure out how to hook the wiring harnesses together between the tachometer gauge, the engine compartment, and the remote control box.

The tachometer I have has only a 4-pin connector on the back. See Figure 1 below.

IMG_4026.JPG
Fig. 1. The back panel of a tachometer and its box.
IMG_4026.JPG (127.54 KiB) Viewed 380 times


I was able to connect the engine remote control main harness, but in that harness there are two bundles of wires. I have no idea where the two bundles of wires [are intended to be connected].

I was sent a two-fuse gauge harness (6Y5-83553-N1-00) that [some unidentified person said] needs to go to the tachometer, but the tachometer only has the 4-pin connector.

I have been working on these wires for four days.

Give simple instructions [on how to connect the tachometer to the engine wiring harness].

jimh
Posts: 11869
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: Outboard Engine Wiring to Tachometer

Postby jimh » Wed May 08, 2024 6:09 am

STANZURAY wrote:Give simple instructions [on how to connect the tachometer to the engine wiring harness].
I am not familiar with the details and many variations of the electrical wiring harnesses and tachometer gauges in the Yamaha engine rigging system, so my advice to you has to be rather non-specific in this case.

If the engine wiring harness you have purchased does not have a connector that fits the 4-pole connector on the tachometer, the most reasonable inference to be made from that situation is:

  • the engine wiring harness you have is not the proper wiring harness to use with that tachometer, or
  • the tachometer you have is not the proper gauge to use with the engine wiring harness you have

The simplest solution may be to use a different tachometer which has individual terminals for connecting the signals from the engine. Or perhaps there is an adaptor harness that can solve the incompatibility between the connection on the tachometer and the individual connectors in the wiring harness.

The dealer who sold you the engine, the wiring harness, and the tachometer will be the best source of information on how to resolve the confusion over the method of connection of the tachometer to the engine wiring harness.

If the dealer is no help, I recommend you visit the forum at

https://www.thehulltruth.com/marine-ele ... -forum-19/

There are several participants in that forum who are experts at the very complicated wiring and instrumentation used by Yamaha. They may be able to offer you advice.