85 12a.
Did a little slide and the gauge stopped working. Completely dead... Still have revs, no gauge

Something to do with the trailing coil iirc?

 

There's a trailing coil lead which sends the signal to the computer for the tachometer, so check your trailing coil and there should be 2 crimp connectors on the spade terminals, one for power and the other for the tach lead. The leading coil only has one spade terminal connector, for power.

You also know that the leading coil is the one in the back, right? Trailing is the coil toward the front of the car - not sure why they did it that way...

 

awesome, i will check everything tonight. thank you

and yes, i have msd blasters that are still fairly new, maybe i didnt tighten everything down as tight as i should have

 

Should just be the trailing coil wire - as stated above. Good luck with it!

 

Found it :p
Thanks!

 

looks like it's barely reaching the connector man, maybe you need a longer wire =)

 

It lets the coil high-voltage leads connect to the dizzy without crossing, which reduces crossfire on long leads (if you space them widely like the factory spacer did.)

 

Both coils produces pretty much the same. Spark plug wire clip keeps them separated. You can leave the wires dangling or without it, it should be fine since the main lead wires are insulated. In fact, the coils on a RX-3 and RX-4 are sitting on top of each other., not side by side like the SA/FB.