Just to clarify, the reverse light I'm talking about when I referenced the grommet is the light under the dash. The car was originally an automatic car, and it now has an A833 4-speed with the stock reverse light switch on the trans.
The harness Bill made is actually two harnesses that plug together. The under-dash reverse light harness has a plug in the engine bay, goes through the grommet/firewall and is terminated with a light bulb socket at the reverse light.
The square connector has only two leads, although one has two wires connected to it.
If there's no plug-and-play for an automatic car that's be converted, any experience on doing the electrical transition will help. Thanks.