SIP Vespa PX Speedo

Hi, Please Help.  How do you connect a SIP Fast Flow fuel reserve cable to the Vespa PX SIP speedometer  2.0. No connection came in the box. So I have bought one and connected to the Fast FlowHowever all 5 connections on the speedo are being used for power, temp,speedo,control & blade connection. Can it be wired into the existing fuel gauge wiring. I have fitted a SIP XL Tank that has no Fuel gauge. 

                     Thanks for you time.

                                   Al.

Sorry can't help you Buganne but I got the same speedo at the end of last year only now got around to fitting it and found no cable/lead in the box to connect fuel gauge although it says in product description it should come with one? Sorry to hijack your thread.

Cheers Graham