Typically, when the board is transferred to new case, the CPU_Fan header is reserved for your radiator fan; since there are 4 different Aurora R1-R4 mthrbrds, I can't be sure if you have an open Chassis_Fan header to plug into, but if you do & if it will fit, u can pop the pump's black 7pin onto a chassis_fan header, as an idea. See link & photos below
Aurora R4, move internals to new case

Two immediate choices: above, buy an unshielded Molex-to-Fan adaptor, or below, place black Molex SL 7pin directly on top of a 4pin Fan header (if the black connector has room to fit)
Below as an example:
- Left: similar Area-51 5pin Molex SL placed atop 4pin fan header
- Center: Basic 3pin Fan Pinout shown = AIO Liquid cooler pinout
- Right: 4pin PWM fan header pinout is shown
5pin & 7pin have same pinout left-to-right; Aurora additional P6 P7 are empty unused

Above, left, Area-51 / Aurora pumps throw a wrinkle in the mix by using a 5 or 7pin Molex SL connector, where ground jumper P5 input is what informs CmndCntr 'Status' = pump is running or pump is failed
The 4pin PWM Fan Header Pinout is shown relative to the 'white tab', where pin4 (PWM Signal) is unused when powering an AIO cooler through the 5pin 7pin black connector (where P4 is empty --> see 'X' ), thus making it 'ok' to pop your pump connector onto any 4pin fan header
On the 5pin example, the positive latch touches the white tab (Aurora 7pin, the latch will face the tab) ... by orienting the latch to the tab you've plugged in correctly left-to-right. Also, you'll know it's mounted correct when P4 (X) is over the PWM p4 --> last, P5 (Aurora: P5 P6 P7) 'touch air'
In other words, above, the black 4-wire 5pin pump motor connector is getting GRD 12V, sending back an RPM signal, pin 4 is unused & the CmndCntr's ground jumper P5 is unused (P5 P6 P7 unused in Aurora)
In the end, the optional Molex-Fan adaptor (2 wires, taps into & sends 12v Grd, which is all a pump needs to run) is cheap & gets the job reliably done: problem solved
If you find a chassis fan header that outputs constant 12v & your 7pin can fit in the space, that's the easy free way to do it
Note: poor cooling performance when using a chassis fan header may indicate fan header is not a source of true constant 12v (if it isn't, pump will run slower & may not run at all) & a new header should be tested instead