Tach. stoped working

[trevs911]

Just replaced rear fuel line and filter along with rear fuel pump.It's all back together no leaks.Took it out for test drive Tach does not work. Is there something I hit,and where does the Tach. get its reading from?

[JFairman]

There's a little skinny black/purple wire coming out of the 6 pin plug on the bottom of the CDI box.
It's the tach signal wire.

It may go into another thin light brown sheathed part of the wire harness depending on the year of your car.

You may have best luck finding it by peeling back the rubber boot around the 6 pin plug and following it from there.
It's the thinnest wire I've seen on the whole car and it's next to the fuel filter so you probably bumped it's connection loose.

If you ever wire into a digital RPM switch for some reason this is the one you splice into.