Tachometer wiring

[jimaret]

I have 1987 johnson 175.Trying to hook up Teleflex Tach .Wiring color on tach are 1.purple 2.blue,3. gray,6. blk. Boat wiring colors are pink 12v ,blue lite , blk grd ,gray tach signal. What should reading be on gray wire with engine running?


Thanks
Jim

 

[Bondo]

Re: Tachometer wiring

I have 1987 johnson 175.Trying to hook up Teleflex Tach .Wiring color on tach are 1.purple 2.blue,3. gray,6. blk. Boat wiring colors are pink 12v ,blue lite , blk grd ,gray tach signal. What should reading be on gray wire with engine running?


Thanks
Jim

Ayuh,... You need a tach FOR a 2-stroke Outboard....

yer color coding sounds like an I/O tach...

 

[Silvertip]

Re: Tachometer wiring

Most tachs are set up for both 2 and 4 stroke motors. However, if you are trying to measure voltage on the tach sense wire be aware that it is not a DC signal -- it is a pulse so you may not be able read anything on either the AC or DC scale. At best it would be a couple of volts. You cannot simply assume that wire colors on a device and wire colors on the boat always match. Your voltmeter should show 12 volts on the "I" terminal of the tach with the key in the RUN position. You simply connect that terminal to the "I" terminal on any other gauge (because they use +12 volts as well). You connect the ground terminal on the tach to ground (or the ground terminal on any other gauge for the same reason). YOu connect the "L" (light) terminal to the light terminal on any other gauge. The tach sense wire in the engine harness goes to the "S" terminal on the tach. You then set the tach for 2 stroke pulses per rev - not the number of cylinders the engine has. Why? Because two strokes get the tach signal from the alternator not the ignition system like a four stroke.

 

[jimaret]

Re: Tachometer wiring

I checked voltage at battery.charging at 13.5 volts when rev eng.Wires all hooked up still no movement on needle,tried on 6p and 2p.gray wire has continuity to rectifier,12v pink,blk grd.

Thanks

Jim

 

[Silvertip]

Re: Tachometer wiring

Do you have 12 volts and ground at the tach? Just connecting wires does not mean the connection is working. If the gray wire is hooked to one of the rectifier inputs, +12 volts and ground are good then the tach is likely toast.

 

[jimaret]

Re: Tachometer wiring

New tach.

Jim