Tachometer Question

[therock19]

i want to install a tach to my 1981 20hp mercury, but i only have a stator and triger, the stator which goes to a terminal block then to kill switch and to switchbox is producing an ac voltage but i get no reading on my tach, i also tried to off the coil itself where ac voltage is present but still no luck, do i need to attach the stator wires to a rectifier then have a wire going back to the tach, or is my ignition stator the worng stator for creating a tach signal. anyone have any ideas

 

[Barnacle_Bill]

Re: Tachometer Question

Look for 2 yellow wires coming from the stator. This would be part of your charging circuit where the tach is normally hooked to. The yellow wires would terminate on a rectifier and the tach lead on one of them since it is a convenient place to attach it.

 

[diaric]

Re: Tachometer Question

try connecting as stated, if it still doesn't work then tell us what tach and what pole setting your using

 

[therock19]

Re: Tachometer Question

i've attached to the 2 yellow wires at the terminal block coming off the stator still no luck, i have teleflex gauges, i've tried the 2p setting and also the 4p setting no luck
i also have a full 12 V to the gauge with good ground

 

[therock19]

Re: Tachometer Question

here is my ignition system setup, very good diagram of it please look and tell me if this helps

 

[therock19]

Re: Tachometer Question

With my VOM i measured the voltage across the signal and the ground with my tach hooked up to the yellow wires off my stator from the back of my gauge at idle i get about 30 volts and when i increase to half throttle i get around 80 volts, why is that so high

 

[diaric]

Re: Tachometer Question

i don't know what your voltage readings should be. hook to just one yellow wire.not sure if you hooked to both or just tried both by your post. teleflex site says to set at 4p or 6p depending on the serial or origin of your motor. if your on the wrong setting the tach will usually bury the needle as if dead.
http://www.downloadingfiles.co.uk/t...structionmanuals/99320 rev 10 Tachometer,.pdf

 

[therock19]

Re: Tachometer Question

i found out from the mercury dealer that on my model i only have 1 stator that is just for ignition, i dont have a alternater stator which i think i need for these tachs, unless there is another way i can hook the tach up to the ignition stator, i will try to just attach to 1 wire, but my 2 yellow wires are all under a screw with my kill switch and a wire going to the switch box, and the 2 white wires go under a terminal screw which i think goes to ground, and that is basicly all the electrical i have under the flywheel

i have tried all pole settings and rpm gause still doesn't move

 

[therock19]

Re: Tachometer Question

here is a pic of my stator and terminal block

 

[ricksrster]

Re: Tachometer Question

If you don't have a battery charging stator you cannot hook up that tach. They attach to the AC side of the Rectifier to either of the yellow stator wires. The tach operates off the charging alternator and not the ignition.

 

[Barnacle_Bill]

Re: Tachometer Question

here is a pic of my stator and terminal block

There are no coils for charging on this stator so your tach will not work. You might check with tiny tach to see if they make one that will work.