Tachometer installation - am I missing something?

[tschwer01]

I've been to hell and back again on my tach project. First ordered wrong tach, then wrong harness, etc.

So I decided to buy the Tohatsu tach and the Tohatsu wiring harness for a 25 hp 4-cyl motor with remote control. These parts are verified (by the marina) to work with my Tohatsu motor and Tohatsu controls. Unfortunately, none of the parts came with instructions.

The problem - I was told that my control would have wires coming out of it that are for a tach install. We walked around the marina showroom and sure enough all the remote controls had some special wires coming out. I get home....I have no wires! I opened up the control, took some pictures and hope someone here can tell me if a tach can be installed. Looks like the only thing happening with this remote is 5 wires going to the motor (and of course the throttle/idle controls).

I also included a pic of the wiring harness end wires (black, white, green and red). So, am I supposed to splice the wires in my control?

Thanks. This has been a month long nightmare.

 

[tschwer01]

Re: Tachometer installation - am I missing something?

Does anyone know why this doesn't have wires coming out of the control for the tach? 2004.

 

[gm280]

Re: Tachometer installation - am I missing something?

Okay not all wiring harness support all options from the motor. I too have the same situation and need to run a few more color correct wires (just to keep in compliance with the factory setup) from the motor to the control unit/box. I think you are experiencing that same problem. You will probably have to run the tach wires as well to hook up your tach. Some of the more experienced folks on here should be able to explain the proper colors to you better than I. But unless you know anything about how a tach works or where to pull that supporting wire/signal from, I’d wait for further advice...

 

[tschwer01]

Re: Tachometer installation - am I missing something?

Ah ok, not happy to hear that my control may be limited, but its a lot better than not knowing anything. Hopefully I get some more info on here. thank you.

 

[TOHATSU GURU]

Re: Tachometer installation - am I missing something?

GM280 nailed it. Multiple control boxes options depending on the model of the engine. IE Box A is for a Model 1 that does not have power trim and Box B is for a Model 2 that does have power trim. Multiply that out over different size engines and you come up with a bunch of possible combinations that aren't entirely correct and allow for plug and play. So, you run your own leads and you make it work...Or you can drop a pot of coin for the correct control box assembly and/or wiring harness.

 

[pvanv]

Re: Tachometer installation - am I missing something?

Yep. Both GM and TG are correct. You can either run a fresh cable from the motor to the tach (using the Factory service manual -- available from any dealer, including me), or drop a few hundred on a new control and harness to get the signal wires up to the front. Personally, I would make up a fresh cable from the motor.

 

[tschwer01]

Re: Tachometer installation - am I missing something?

yes, my control is not designed to handle a tach. glad I got that settled. thanks.

wiring diagrams are not clear. is there anywhere I can go to find a manual or picture that shows how I connect the 4 harness wires (as seen in the picture above) to the motor. i opened the motor cover today and almost got dizzy trying to interpret what would connect to a tach. Jesum crow, why is this so abstract? My local tohatsu dealer doesn't know how to do it. They only deal with remote controls that have the tach wires built in. I don't want to buy a new control.

Thank You.

 

[pvanv]

Re: Tachometer installation - am I missing something?

Tim,

Aftermarket manuals are a waste of money, especially on the MFS25/30 -- they cover a lot of models, and are too general to be really useful. The Factory service manual has full wiring diagrams, and is excellent. It's copyrighted, so it cannot be downloaded for free. BTW, you do not have a 4-cylinder motor; it's a 3-cylinder 4-stroke. There are 2 versions of the manual, available from any dealer (including me): the early one with carbs (the 25A), is service manual# 003-21053-0, is $40.00, and the 25B, which is EFI, is service manual# 003-21054-1, is $50.00. Which motor do you have?

Regardless, at the motor, the white and yellow are the standard Tohatsu/Nissan tach signal wires. You will also need switched power, ground, and instrument lighting (if desired). No need to buy a new control box -- just run the tach wires to the tach, 3R0725371M, LEAD WIRE, METER, $58.94, or get a new control box harness that has the wiring in it: 3A3761151M, CORD ASSY B (20 FT.), $152.04. These are available from any Tohatsu/Nissan dealer, including me.

You can drop me an email at the office: paul@obersheimersails.com, or call 716-877-8221 M-F 9-6 Eastern, and we can help you get this straightened out.