Hi all. I feel like I'm in the Twilight zone. I recently bought a $20 sequential shift light off of Facebook marketplace and while it powered up and configured properly it didn't seem to actually do anything in relationship to the tech. It was wired into 12 volt power black ground and tach signal. I wired it into both the OB diagnostic connector under the hood as well as the wiring behind my gauge cluster and no dice and either case. I chalked it up to it being for some type of distributor-based system and moved on. Just for poops and giggles I bought a shitty big bullet style shift light from Amazon and tested that on the car and it worked perfectly plugged into the same 12 volt negative and tax signal behind my gauge cluster. About the only thing that was wrong with it is it wasn't a sequential shift light and from time to time it would blink erratically on its own. Fast forward and I decided to purchase a for real shift light this time and I purchased a Cartek Club. I wired it into the same 12 volt ground and tach signal behind the gauge cluster. Once again although it turns on and I can go through the configuration process it doesn't seem to actually pick up a tach signal at all as when I read the engine no matter what the settings are on the low and high RPM the lights never light up.

I'm super bummed out and have no idea why a shitty $20 Amazon shift light would work just fine but this $150 one which has all the bells and whistles I would ever want doesn't. I've also hooked it up to the OBD2 diagnostic port under the hood and the same result happens. It is set to two pulses per crank which I believe is the right Miata spec although switching it I'm not sure helped. Any advice on getting this up and running would be fabulous I'm desperate.

 

Hey did you guys know that green and blue aren't interchangeable? Apparently the boys in the UK like their tach signal wires blue while the boys in the land of the rising sun like them green. Well, when you figure out which is which, you get a working sequential shift light. Thanks!

 

You were wiring things into the car based on wire color alone, instead of using a wiring diagram?

Oops.

 

I want to say no. I read the diagram and then just brain farted and went red is power, green to green and blue must be ground. To be fair to my brain, the shift light I removed was wired up that way. Anyhow, all working now!