75 horse Johnson-Tachometer w/ no signal

[nanderson]

I have a '77 johnson 75 horse and I cant get the tachometer to work. I am getting the 12-16 volts between ign. and ground on the tach like it asks. I tested the grey sender wire to the lead on the engine and thats fine. The instuctions for the tach say if there is no lead for the grey, then hook up to yellow or yellow grey, which seems to intersect between stator and rectifier. Still no luck. the motor seems to run fine and there is ac current coming from rectifier. Any suggestions. <br />Thanks nanderson

 

[rickdb1boat]

Re: 75 horse Johnson-Tachometer w/ no signal

Sounds like a dead tach. Borrow another ot take that one back. If you're sure you've got at least 12 volts to the ignition terminal and the rectifier is putting out, it can only be the tach. You do have it set on 6 pole, correct?

 

[nanderson]

Re: 75 horse Johnson-Tachometer w/ no signal

Thanks for the reply Rick.<br />I haven't had a chance to get a tach yet. I also<br />forgot to mention that I tried testing between the yellow and the yellow/grey wires and didnt get any response only from the rectifier that it showed juice. It doesn't seem to make sense. what should I have my tester at? I tried it at ac 10 setting.<br />Thanks nanderson

 

[R.Johnson]

Re: 75 horse Johnson-Tachometer w/ no signal

With your meter set on DC voltage what whasthe reading on the gray tach. wire. As I recall! it should be about 9 volts. If you have no voltage here, check rectifier

 

[rickdb1boat]

Re: 75 horse Johnson-Tachometer w/ no signal

Has your charging system been working OK lately?<br /><br />Try this:<br /><br /> web page<br /><br />If need be, you can get one here:<br /><br /> web page<br /><br /> web page 2

 

[gaugeguy]

Re: 75 horse Johnson-Tachometer w/ no signal

If you have your 12 volts and ground at the tach and between 3 and 7 volts AC on the gray wire, the tach is more than likely bad.

 

[nanderson]

Re: 75 horse Johnson-Tachometer w/ no signal

Thanks everyone,<br />It turns out that my rectifier is bad. I got a new one I just haven't put it in yet. We'll see.<br />Gaugeguy, I used to live in Keene, not much boating in the winter.. Thanks nanderson

 

[gaugeguy]

Re: 75 horse Johnson-Tachometer w/ no signal

nanderson, I used to live in Encinitas. A lot more boating opportunities where you are. There is already Ice forming on the lakes here.