My replacement JST came in a different color order.

I assumed the fan I bought would have the same colored connection as the original one. Result: positive.

So I did switch the black with the red color. But be sure to check which cable colors your JSTs come with and which order they have.

Check step 2: Remember the connection order. You might break something.

The connectors have to match with the board. Otherwise the fan is spinning the wrong direction.