I wired this up a couple of years ago, works fine usually even if it's a bit glitchy. But it definitely indicates the correct speed most of the time. The question I have is, why doesn't the odometer work? I wired it up according to the instructions and the speedometer works, so I had assumed the odometer would be linked to the speedometer, but apparently it isn't. Has anyone else dealt with this before? The car is carbureted with a T56 at this point, so maybe it has something to do with the ECM being removed?

The closest thing I can find to a wiring diagram is this:

https://austinthirdgen.org/storage/diagram_1992_gauges_part5.gif

https://austinthirdgen.org/storage/diagram_1992_VSS_V6_vinT_and_V8_vinF_and_vin8.jpg

It just worked before my T56 swap and then it didn't. I cant find any explanation for it.

None of these indicate there are any extra connections to make with the SGI-5 so Im stumped.

 

Your plastic gear that drives the odometer is probably broken like so many are. There's a kit available to replace it. You need to take your speedo out to check

 

Well that explains it. I didn't realize it was such a common issue. Just figured if the speedo worked so would the odometer, kept thinking it was an electrical issue. Makes sense that it's likely a mechanical one.

I did manage to find the replacement gear, so thanks for pointing me that direction.