Don't know about the '53 but the sender is attached to the right-side post of the fuel gauge on a '54. The wire goes directly to the tank sender unit (the sender wire has a splice connector somewhere behind the master cylinder).

On the sender post of the '54 gauge is a cardboard label with a warning not to attach the hot lead to the sender post. The hot lead can come from the ammeter gauge or from ignition switch (a lead that is only on when the ignition switch is on).

Since the '53 gauge is different from the '54, wait to hear from someone with correct information about which lead is hot and which lead is for the sender.

By the way, just in case you have a 12v conversion, a 12v system with stock fuel gauge needs a Runtz resistor on the hot side of the gauge.

Make suure the gauge cluster is well grounded and the sender unit on the fuel tank is well grounded.

Tim