I just traced a mystery second wire, attatched to the + side if my coil on the 70 B. It runs into the harness thast goes under the car and to the fuel pump. This was traced because when I first hooked up the new pump, the tach went nuts, without engine running, as the pump started filling up the floats. the tach would swing up and down in sync with the ticking of the pump. Is this connection standard or a DPO thing. Once I fired it up she ran fine, but the tach continues to go all over the dial. Any thoughts?