Tachometer install, help needed.

[Jacob J]

Hello all

First of all, I am sorry if this is posted in the wrong place, but it seemed the right place for me. Please move this topic, if it is misplaced.

Now. I have a mercury 25hp bigfoot 4-stroke from 2001. To that engine I have connected a quicksilver control box like this one:

http://www.boatpartsandspares.co.uk...ges/mercury-mariner-remote-control-1430-p.jpg

Now I want to connect a tachometer because I have read that you need to check the rpms at full throttle to see if you got the correct prop on the engine. I think the engine is not at full rpm, so it would be cool if I could get the last top speed out of it.

As you can see on the picture, there is a piece of wire with a plug on it comming out of the control box and close to the end of that plug there is a brown wire. Am I right in the assumption, that this wire is the tacho signal? I am new to this boat electronics, so please have that in mind if I ask stupid questions. But if we assume that this is the tacho signal, and please correct me if I am wrong, then I hook that up to a tachometer and connect the tachometer to 12volts and ground and it should be all alright?

Thanks if advance for your time

/Jacob

 

[Frank Acampora]

Re: Tachometer install, help needed.

I THINK the wire and fitting you showed is for power tilt/trim.. Difficult to say because sometimes Mercury had these wires inside the cable and they connected to the switch in the handle. At the engine end they were outside the main cable and simply plugged into the tilt/trim wires.

You would most likely do better asking on the Mercury forum.

 

[Jacob J]

Re: Tachometer install, help needed.

Okay. I will post the topic there.

I have trim buttons on the handle and it works. Do I need a special mercury gauge or can any gauge work, if I find the right wire?

 

[MH Hawker]

Re: Tachometer install, help needed.

The drop out rubber plug is where a accessory cable plugs in and that includes a tach. No it will take most any tach as long as its set to the right pole/pulse setting. You need to buy the accessory cable and that will have the wires you need.

 

[Jacob J]

Re: Tachometer install, help needed.

Thanks for the answers.

Would it not be possible to hook right in to where the gray cable ends on the engine, so I could skip buying that cable. I bet that it isn't easily avaliable here in Denmark.

 

[MH Hawker]

Re: Tachometer install, help needed.

Yes you can but you will need a 12 v power source from a switch to turn the tach on and off and a ground. and a signal. Thats why their out of the controller, The purple is a switched power source, gray signal, and black is ground. You can splice into the wires that come out of the controller.

 

[MH Hawker]

Re: Tachometer install, help needed.

Here is a print on just instruments.

 

[Jacob J]

Re: Tachometer install, help needed.

Okay. But then I think it would be a hole lot cheaper for me to connect a tachometer through a switch to the main battery and and then get the signal directly from the engine. I would rather not split the plug apart. Maybe it would be possible to find some pins that could go into the plug? Is there something like that around?

 

[Jacob J]

Re: Tachometer install, help needed.

Okay. I have now got hold of an tachometer a local dealer was willing to give me for try the weekend over. Ive got it installed. 12v to purple, grd to black, and gray to signal. Nothing happens. Ive measured 14v across the 12v and ground when the engine is running and 2.80volt across the signal and ground, so it is getting a signal I guess. Is the tachometer dead or are there any other things I could try before returning it?

 

[Jacob J]

Re: Tachometer install, help needed.

Any thoughts?