Carb to injection, wiring for the fuel gauge

Hey guys, Just wondering if anyone knows which wire goes where. Carb wiring has a purple wire and a brown wire for the fuel gauge but the unit on the tank has 3 pins. Tried all the combinations but cant seem to get a reading on the dash. Running an inline pump so no wiring into the tank, just the fuel gauge wiring.

Cheers
        Jamie

take the sender out and look at where the pins come out on the bottom.

the sender wire will be the one going to the resistance track, the pump live goes to the lifter pump only. the earth wire is shared between the pump and the resistance track.

should be pretty easy to work out

Are you using a lift pump? I'm guessing not but just confirming. I'm having a similar problem as I converted my carb to injection using a lift pump and now my fuel gauge displays full constantly. Its not ideal for obvious reasons, but It doesnt stop me driving it, but it would be nice to know if you fix it.