Tachometer installation

[seicam]

I have ordered a tachometer for my Honda 20 engine. I picked the one suggested on the other thread hear (I think by Ron) - Honda/Faria unit model no. 37250-ZW5-010ZA. Got it from boats.net for a good price. Here is the question:
The tachometer came with no wires. From some discussions in other threads it seemed that there is some ready harness that can be plugged into it and into the engine control unit. If someone had purchased that, could they share some more details, like model no. , etc. ? If that's not the case, then I will need to make my own I guess.

Thanks,
Maciek

[Jerry]

Interesting timing as I installed mine yesterday.

The way I did it was to put it in the same place as Ron – Starboard rear of the locker so I can see it when sitting on the port side.

Mine did not come with the wiring and when I looked on line all I could find is a wiring harness for a whole set of gauges and I do not remember the cost but it was close to (or higher then) the price of the gauge itself so I made up my own wiring harness.

If you look at the wiring diagram in the Honda manual in the upper left you will see the three wires that come out of the rear of the remote throttle (in Port locker). The wires are Black, black with yellow stripe and grey. They coincide with the posts on the rear of the tack for GRD, BAT and SIG in that order. The connections each have a little rubber plug in them and once the plug is removed each is a Female snap connector. So basically all you need to do is run each wire (min 18 AWG – I used 16AWG), install a male snap connector on one side (to connect to the harness) and a ring terminal on the other end to connect to the tack. (the other wiring in the port locker photo below is from the factory installed tiller auto pilot connection)

Because the wiring diagram also shows a fuse in the BAT line I wired a 5 amp fuse in line. The wiring diagram shows a 10 Amp fuse but my assumption is that is for the entire gauge set so I down sized and will carry both sizes as spares.

Another connection on the back of the tack is for the light which can be wired to a separate switch but I just connected (with a ¼” female blade connector) to the BAT terminal so it will be on whenever the ignition is on.

Biggest issue I had was finding a 3-3/8” hole saw – I bought one from tooltopia.com. It ended up costing me about $22 with shipping. I would not suggest drilling a larger hole as this fit perfectly.

I will not get to check operation until firing it up in about a month but it was a pretty straightforward installation. I ran the wire parallel with the others that run through the rear bulkhead and I just cut the wire ties and added new wire ties adding the new wire. I also added a couple new places to wire tie to as I have found the factory did not put enough of them in IMHO.

Overall not a tough job

[Ron]

Maciek, Jerry -

I'm in Pensacola now. Jerry got the same tach as me. I may be wrong about the wiring harness - I could have made it myself, don't remember. When I get home I'll take a look. It plugs inot the 3 wires on the remote control per his photo's and description.

[seicam]

Thanks a lot Jerry. Really good description and photos - I will follow those, should indeed be straightforward. From the photos it looks like I got the same exact tach model.

The biggest challenge I guess will be drilling a hole in the starboard locker. I have not drilled in fiberglass yet

Thanks,
Maciek

[Dan]

Run the hole saw in reverse after getting the center pilot started. This will prevent it from cracking/chipping the gelcoat. Once through the gelcoat, run the hole saw normally. If you have good access to the back side, finish the hole cut by drilling from the reverse after you're part way through the laminate. This way, you won't tear up the laminate on the inside of the locker.

Thanks a lot Jerry. Really good description and photos - I will follow those, should indeed be straightforward. From the photos it looks like I got the same exact tach model.

The biggest challenge I guess will be drilling a hole in the starboard locker. I have not drilled in fiberglass yet

Thanks,
Maciek