Picked up a Guage cluster with factory tach. My truck is a 1986 f150 w/302 aod. Has tfi ignition. I plugged the new cluster in an all gauges work except the tach.

My question is what do I need to do to get the tach to work?

 

Are there and wires disconnected on the engine coil? As stated in another post the PO thought he was a wiring expert he may have deleted the wiring in the harness that feed the tach.

Hope this helps

 

Also check the back of the tach. On some earlier ones there was a dial to turn for 6 cylinder or 8. Just a shot in the dark.