Tach signal wiring
 

I bought an 86 base model a few days ago with no gauges working except the speedo. It was blowing the meter fuse as soon as I turned the key to on. I took the gauge cluster out and the fuse didn't pop, so I started plugging stuff in back in and checking each connection, but it never blew again. The idiot lights now work and I got some gauges working, but still no fuel level or tach. The car came with a new fuel level sensor so I will replace that before looking into more wiring problems. After searching through the forum a while I found that the tach signal is coming from a bullet connector on the trailing coil. There is nothing plugged into that, and I can't figure out where it's supposed to go on based on the FSM. There are also a few green connectors next to the coil that are disconnected, I have no clue what those are for.
https://cimg0.ibsrv.net/gimg/www.rx7...919cf62f67.jpg

Yes, the tach gets its signal from the trailing coils, but the bullet connector that you're referring to serves as a test connector. It's normally not connected to anything.

Your picture is of the leading coil. The trailing coil is by the firewall.