Do all other inputs to the system such as throttle, brake sensors etc have their own dedicated sockets to plug into or perhaps are they expected to share the same 12 pin plug input as the display using the otherwise unpopulated pins?? the picture in the ad linked to certainly does not employ 12x connections regardless of the plug size employed.
How many actual wires are connected to your display 5X? 6x? generally there is
1 Battery voltage,
2 Key lock (Turns the system on when connected to pin #1 battery voltage)
3 ground,
4,5 Rx Tx??
6 ? 2nd wire in the pic suggests a wheel magnet speed sensor input too?
as it looks like your expected to build the plug yourself with the display in the ebay listing, the pinout should be available? if so wiring your current display up should be ok for testing with a bodge connection secured with blutack/tape.
if not already done google for a detailed manual for your display unit as it will list all the error conditions it can display when connected for further diagnostics if required As well as the required pinout info for connecting. (including .pdf in the search string should include a page count with relevant results so eliminating the few page intro manuals is easy..)
