Tach not working

[jeff6898]

HAve a 2001 NItro 700 LX 2001 90HP mercury. The tach doesnt work. SOmetimes the needle will bounce a little when I first start it up. Other then that it just sits there It looked like the wires were hooked up good to the back of the tach. Don't know where to look on the motor to see if they are hooked up

 

[seabob4]

Re: Tach not working

First make sure you have good power to the tach. Check voltage across the purple and black wires. Should be 12V at least. Then, with the engine running, check the voltage on the gray wire, that's your tach sender wire, should be around 5.5V.

Can't say exactly where the sender wire gets it's pulses from on the motor, but I'd guess somewhere under the flywheel on top of the powerhead.