Speedometer and Odometer not working
 

Hey guys, just looking for a little help in the diagnosis of my problem here before I start working on my car.

I had a very strange issue with my CPU no2 where when the interior of the car was cold i got some strange results. There was a consistent turn signal noise and flashing seat belt light, and the power windows would only work intermittently between the flashing light and noise.

The CUP no2 on the car has in white letters F110. The car is a RHD 94 Manual rx7, and i was unable to find a exact replacement of the CPU no2 so i replaced it with a CPU no2 that had the letters F100 which leads to the next part of my story.

When i put in the F100 CPU no2 it solved my issue but led to another where my Speedometer and Odometer stopped working. Initially i was not bothered by the issue and just drove it without a working speedometer, but i eventually ordered the correct CPU no2 F110 but the speedometer and odometer did not go back to functioning as normal.

So now my assumption is that it was coincidence that the speedometer and odometer stopped working at the exact same time i replaced my CPU no2?

From my research the speedometer and odometer work together so I assume that when i find the issue it will solve the other.

Is it possible that the CPU no2 is related to this issue?

From research it looks like the speedometer cable is the first thing to look at, where about is it on the transmission?

I believe i was working around one of the front wheels on that day, is there anything in the ABS system around the front wheel that would work with the speedometer or is that independent?

Any advise is much appreciated. Thanks

well... the speedometer doesnt have a cable. its electric. i forget where i was reading it but the cpu no2 are suspected to be from different trim levels. i wasnt able to find what the exact differences were between them but i believe one of them has an extra or different plug. regardless, try this and see if it helps you out

https://www.rx7club.com/interior-ext...epair-1055763/

as for fixing the speedometer, does it not work at all or do at least have your mileage showing?