Answer by Simon Fitch for Force equal current between 2 pins

A little ballast resistance in each path will help share current equally between them. First look at the current imbalance without ballast:

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^{simulate this circuit– Schematic created using CircuitLab}

Here the fuses represent the connectors, and R3 and R4 are cable/connector resistance, slightly mismatched.

Now insert some small but deliberate additional "ballast" resistance in each line:

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^{simulate this circuit}

That's brought the currents much closer together, at a cost of about 0.2V total lost across the resistors. They will be dissipating about 1W, so make them beefy.

Active solutions will be complex, and probably won't have any benefit over the above. Still, if you don't mind getting your hands dirty, here are a couple to ponder.

This next circuit doesn't share current equally, but it does clamp current through one path (via the 130mΩ resistor) to a maximum of 5A. When that threshold is reached, Q1 begins conducting, sending all additional current via that route instead:

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^{simulate this circuit}

This circuit will lose 0.7V, and dissipate over 3W in R1 and Q1, so be sure to heat-sink transistor Q1, and use a beefy resistor.

This is how currents are distributed as I ramp load current from 0A to 10A. Blue is current through ammeter AM2, and orange is AM1:

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If that 0.7V drop is too much, then you'll need to use a smaller current sense resistor, the voltage across which will require amplification. In this next design, R1 and Q1 dissipate only a little over 1W, and the voltage lost across those elements is only 0.2V:

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^{simulate this circuit}