Tachometer problem

[alamosaddles]

Question about my tachometer. Not sure which forum this question should go in, if this is not correct, please have a mod move it to the correct forum.

I have a 2003 Johnson 150. My tachometer is now not working (as in, not reading the rpm's) however, the diagnostic (idiot lights) lights on the tach are in fact operating fine. This tach is a teleflex, and has rpm readings of 0-70 x 100 rpm, and has four idiot lights. they are red led's and are marked low oil, chk eng, hot and no oil. Can anyone guide me as to how do I check the tach to insure the tach is bad, and if I need to replace it, does anyone know where I may find a tach with compatibility for my motor/harness/idiot lights?

The wire from the harness that comes from the engine is correctly sending the required voltage all the way up to the tach harness. Voltage is approx 3.5 at idle and rises as the throttle is pushed, so I know the voltage is there, just that the tach is not displaying diddly. Is there a simple procedure for me to determine the tachs viability?

 

[alamosaddles]

Re: Tachometer problem

Anyone?

 

[DRIFTER_016]

Re: Tachometer problem

The tach should have 2 other wires besides the signal lead that you already checked. There should be +12 volts on one and the other is a ground. If these are good it's probably the tach. The only definative way to tell is to hook up another tach and test it out.
To get an exact replacement you will need to talk to the boat dealer/manufacturer as it was more than likely ordered custom for the application.
You could put a regular tach in and just leave the idiot lights disconected.

 

[alamosaddles]

Re: Tachometer problem

The tach should have 2 other wires besides the signal lead that you already checked. There should be +12 volts on one and the other is a ground. If these are good it's probably the tach. The only definative way to tell is to hook up another tach and test it out.
To get an exact replacement you will need to talk to the boat dealer/manufacturer as it was more than likely ordered custom for the application.
You could put a regular tach in and just leave the idiot lights disconected.

I have considered doing that. My concern/question is, if the engine will function properly without the System Check part connected. I will get another tach and test that out tomorrow. Do you know if a tach is repairable and if so, anyplace that is known for doing such repairs?

Thanks for your input so far.