Smartcraft compatibility

[Nasher]

A simple question that I suspect may not have a simple answer.

Will a SW V4.00 Smartcraft Speedo and Tacho @2007 work with a 2003 Optimax?

I'd use the correct later Speedo and Tacho Smartcraft Harnesses with the separate Earth connections rather than the earlier ones with the ground coming from the Smartcraft Junction box.
But not the later V6 onwards harnesses and gauges.

Ta

Nasher.