Hi, guys. First post here.

I've always wanted a tach in my Nissan 1400 but they are few and far between here and get snatched up so quickly. I eventually found a Datsun 1200 GX someone was stripping and got an OEM induction loop tach from 1973. Unfortunately the Datsun was a non-runner so there wasn't any way to see that it was working but I decided to take my chances.

Anyway, I recently rebuilt the wiring from front to back of my bakkie and deleted the ballast resistor as you don't need it with EI. As recommended on the tech wiki page, I wired the tach in series with the ignition switch and the positive terminal on the coil. Bakkie starts and runs perfectly but no tach reading at all. The tech wiki does say that the early Datsun tach's work with both points and condenser ignition and electronic ignition. However, so many other forms out there say that induction loop tach's don't work with electronic ignition systems?

I tested all the grounds and the separate 12v for the tach and everything seems fine there.

I was wondering if anyone had any other wiring suggestions I could try? My other idea was to swap the points and condenser back in with the ballast resistor just to see if the rev counter even works, but thought I'd ask here first in case there's a simple fix.

Thanks all.

Interesting problem

Another way to test the tach is to "temporarily" connect it to a friend's old ford/chevy/datsun. Use jumper wires for earth (black wire), battery + (red or yellow wire) and disconnect the wire to the coil and connect to the loop, and jumper the other end of the loop back to the coil. It will work even with a six-cylinder or V8 engine although the reading will be off


The original tach works with Datsun EI, but some people have problems with non-Datsun systems (or incorrectly wired systems). Which EI exactly are you running?

A ballast resistor is needed or not needed mostly by the coil. Some EI coils require a resistor, some don't. You could try putting it back in and see the tach starts working. All EI system will work with a ballast resistor, and the early Datsun EI required a ballast resistor

I would also fit the condenser that came with the EI system