There are two wires that go to the fuel tank,Ithink fuel sender wires you need to join these together to stop the revcounter needle jumping.

Rather than joining the wires together in the loom, why not connect the loom wires to the wires from the tank sender?

If they are connected correctly, you also get the fuel light on the 600 clocks!
You might need to modify the Cat loom to put the 3TJ connectors on, but if you have the fuel pump running correctly, then this must have been at least half done.



The two connectors in this pic are for the fuel pump (left) and the tank sender (right).

Alex.