I have a 97 Mazda - 323 S V (BA) - 1.8 i 16V (114 Hp) with a manual 5 speed transmission. While trying to change the oil, I noticed the following connector, with one missing wire on what I think is the transaxel housing:
There is a similar connector on the front driver's side of the transaxel housing ( if that's what it is ). The little red circle is the broken wire, the large yellow circle the "senosr" or whatever it is.
This wire looks like it's been broken a long time, and there's no MIL and last time I connected to the ECU there weren't any error codes present.
I've been looking through the service manual for a similar model ( the 96 Protege ) and so far I haven't been able to find anything. The service manual can be downloaded here.
The section for the transaxel starts on page 394.
Here's a similar looking "sensor" on the front side of the transaxel, next to the driver's side front wheel: