Quoted from AUKraut:
Herg: if you could take a pic of this it and the resistor specs it would be great to have for reference!
I used 2x Xicon 280-CR10-3.0-RC, 3 Ohm, 10W, wirewound resistors. They're cheap enough that I would suggest getting multiple values to try. I tried pairs of 1-5 Ohms and settled on the 3 Ohm. I added connectors and just plugged in between the motor and harness.