Tachometer acting funny

[blueoval78]

I just installed a Faria tachometer on my 1988 Force 50HP outboard. When I turn the ignition key to on, the needle slowly starts climbing and when I start the engine it climbs past 7000RPM and stays pegged at it's maximum position. I specifically selected a 20 pole tachometer from Great Lakes Skipper. I hooked up the purple wire on the motor that said tachometer to the signal post on the back of the tach. I then got power for the light and gauge from the instrumentation wire in the dash of my boat. (Both are feeding from the same power) I grounded the gauge to the same ground as the instrumentation.

Any ideas why the tach is acting funny?

 

[SweeperForce]

Re: Tachometer acting funny

Is your rectifier working? If I may ask why did you get a new tach? I'm not sure what your wire color is but the signal wire should run back to one of the ac wires coming from your stator into your rectifier. Sometimes you can switch to the other ac wire if you are getting a weird reading.Here's a picture I hope it helps.





Tom

 

[blueoval78]

Re: Tachometer acting funny

The charging system seems to be working ok... The boat did not have a tachometer so I installed one to figure out if my boat is propped correctly. The purple wire is coming from the junction block and it is labelled tachometer so I figured that was the correct wire. It was run from the factory to under the dash and taped on the end - I presume for people who ordered the tach option. The funny thing is when I turn the key on, the needle starts climbing slowly on it's own before the engine is started. Is that normal?

 

[SweeperForce]

Re: Tachometer acting funny

No that is not normal. After I turn on my battery and turn the key to activate the accessories my tack pegs "O" and stays there until I start cranking. I hope others will post reply and be more help. Sorry.

Tom

 

[geeco1]

Re: Tachometer acting funny

I just installed my tach, and I too used the purple wire. It seems to work for me. When the ignition is off, the tach needle is resting below zero. When the key is turned to the "on" position, the needle jumps to zero. After starting, the needle pops to 750 rpm.

HTH

 

[blueoval78]

Re: Tachometer acting funny

Where did you grab power and ground for your tach? i think i might be getting interference - i grabbed power and ground from instrumentation lighting.

 

[jerryjerry05]

Re: Tachometer acting funny

The purple lead is probably a power lead.You need to look for a grey lead.Maybe the wires are crossed.J

 

[blueoval78]

Re: Tachometer acting funny

My boat is a 1988 Bayliner Capri 1500 - has anyone ever hooked a tach to this type of boat before? I assumed the purple wire under the dash was the signal since it was purple leaving the motor...

 

[geeco1]

Re: Tachometer acting funny

Under my dash is a small electrical strip that has 4 connectors. (see pic). The purple is Tach Signal, the Red is power controled by key switch. I then ran a ground directly to the neg. side of my fuse panel.

 

[blueoval78]

Re: Tachometer acting funny

Ok, looking at my outboard again, I have multiple wires going to the dashboard. The aforementioned purple one labelled tachometer, as well as 2 wires labelled magneto - 1 white and 1 blue. Could the purple be the power and either the white or blue be the signal wire?

 

[blueoval78]

Re: Tachometer acting funny

Solved!

Great Lakes Skipper made a mistake in their product description. The tachometer I bought was only good up to 12 poles; despite their website indicating it was compatible with 20 poles. There was even a #6 setting on the back of the gauge which I assumed was for 20 poles. I turned the adjustment down to setting #5 and the tachometer operated properly, albeit 1500 RPM's too high. Great Lakes Skipper has agreed to refund the money but I will still be out $60 in duty and taxes for the product coming across the border. Sigh...

Guess I should've done more research before buying the gauge set. Anyone know where I can get a 20 pole tach?

 

[geeco1]

Re: Tachometer acting funny

I bought my 20 pole tach from Greatlakesskipper just about a month ago. It is stock number 1017268. I just checked and they indicate online that they have 43 left in-stock. I have installed mine and it appears to function correctly.