Help Trouble with Rpm not working what to do and where to start

Hey I am have trouble with my speedguage. After coming back from church this morning my speedometer gauge was working find. later on in the afternoon I wanted to go to the store and i noticed it was not working. any ideas please help Oh yea it is a 89 honda civic with a b18 swap

Your car has a B18 swap, but you aren't sure about 'your Rmp' (later 'Rpm')???

You mean your Tachometer, Tacho or tach???? It has a B18 swap, so I guess you bought the car already like that, right? Shit, get to know your car.

First thing:check no wires have fallen off & it's all connected.

When I said Rpm i meant speed guage so can any one give me a few pointes on where to start or what the problem is ?