993944S2

I've read most all the posts I can find and I'm not sure what to do next. See picture. The green wire comes off the negative side of the coil. It loops around the back of the engine, then is looped and spliced (as per picture) into a green wire in a harness. That harness goes up over the engine and carries the injector wires and the sensors close to the air box.

On the right you can see a green wire cut. This wire goes into a harness and through the fire wall. It is cut on both sides of the white connector. On the left side, where it is cut, the wire from the coil is spliced into it.

Car runs fine. It is a race car so I do have a cut off switch. That works fine. The mileage gauge above the tach works. Just no tach. Any ideas greatly appreciated.

Don

Lizard944

Not sure about the wiring, but my tach gauge is sometimes lazy in the morning. With the vehicle running, I just use my fist to rap against the clear plastic instrument housing and the tach springs to life.

odonnell

That green wire is the tach signal. That 9-pin connector is the interface between the DME harness (originates the coil firing) to the body harness (which contains the wiring to the coil). On the right half, there's a smaller green wire that also comes off the DME coil signal wire (thick green one) and goes to the tach. The tach is triggered by coil firings.

So, you should be able to marry the wire coming from the coil to that wire to reestablish tach signal input.