Question about fuel gauge wiring.

Hey guys I've been trying to get my fuel gauge working for a few months (one weekend at a time) and have gone through the entire system starting back at the tank

The car now has:
A brand new fuel tank.
Brand New sending unit which is ground to the frame.
A brand new mechanical fuel pump
New rubber hoses at every connection point.
Brand New fuel gauge.
Brand new voltage limiter.

I also made a point if flushing the steel fuel lines when I was replacing the tank. Problem is the gauge still doesn't move. At all.

When reading other threads on here I saw someone say that the wire with the angled connector on the sending unit goes straight to the fuel gauge but when I took out my instrument cluster there were no wires connected to the gauge at all.

When I got the car there was an after market fuel gauge mounted to the bottom of the dash with a tangle of wires all spliced into each other that came from a cluster behind the left kick panel. That gauge never worked either.

My question is should there be a wire connected to the back of the fuel gauge in the instrument cluster? And if so where does that wire feed in from?

My assumption when I took it apart was that the wire from the sending uniting ended up in the loom connected to the back of the instrument cluster and that the gauge received the signal via the circuit board.

I have a physical manual but the diagrams are a bit confusing when comparing to actual locations within the vehicle. Any help would be appreciated.