Hello! I solved the same problem with the DM380 motor. My receiver is zgemma h9s. You need to find the point after separating the Usals and + 12V signal, unsolder it and apply external power from the + 12V unit with a current of 2-3A. Good luck!
https://yadi.sk/i/p4Zv4yNlWxj68A
P.S the break point (red cross) must be higher - between L2 and R. Power supply to L2 from below. Sorry, I made a mistake
Try this : https://www.satelity.ellano.sk/obmedzovac-prudu_38877.html