Rev counter not working

[diverjohn]

I have a Yamaha 115 hp, four stroke 1999 it's done 3,800+ hrs and still runs well, I have fitted a new rev counter/trim indicator, the original one's screen went. Now the tilt shows but the revs do not, they only appear when you are operating the tilt and go off as soon as you release the tilt switch, I have checked all the wires but still wont work, any ideas what may be wrong?

[boats.net]

Sounds like a wiring problem, incorrectly wired or bad connections.