Raylar

If you boat around sand bottoms as a lot of performance boaters do, get your strainer, even if you have one, replaced with a sand strainer like the ones that CP Performance sells.
These sand strainers are not cheap at about $400 but the damage to engines, pumps and weekends from sand damage is even bigger. Just a thought !

Best Regards,
Ray @ Raylar

PS- Go to the ten pin connector and find the gray wire and trace it back on your engine harness and look for a problem if its wiring. Then you can go go forward in the boat and to the guages themselves and hopefully you'll find your gremlin..

blue thunder

If you run a wire from the - of the coil (grey wire) to the "sig" terminal on the tach you have completely bypassed the grey wire. Also, with the ignition key on check for 12v at the back of the tach and chech the ground wire on the back of the tach for resistance to ground, without key on.

Panther

Test the grey wire behind the dash that's connected to the tach, not the end of the grey wire where it's attached to the coil....

You will confirm/deny within a minute or two at that point if you have a bad tach or if it's the wire or a connection somewhere in-between.... I found it's easiest to test it this way before diagnosing further since you're not taking anything apart yet... Always check the stupid stuff first...some guys will have the whole engine apart...

since you're here in NJ you can feel free to call me and I'll walk you thru it.. PM me if you're interested.

NJDave

Thanks guys for all of your help. Raylar I could not agree more. I only go to the shore 1 week a year but we are looking to buy a shore house in the next year & if we do I will have the boat down at the shore house on a lift in the back of the house & I will for sure be putting on strainers. As for the gremlin. I would not have believed it if I did not check it my self but the Tach is the problem. I un plugged the working side & removed it because the wires would not reach & then from behind the dash I connected it to the non working wires & I worked. Go figure what a coincidence! Lesson learned always check the simple stuff first & save the harder trouble shooting for when you have no choice! Thanks again guys. I guess I will be sending my tach back to Livorsi.