BMW E30 M50/S50/M52/S52 wiring harness adapters BMW E30 M50/S50/M52/S52 wiring harness adapters Are you planning on swapping your a m5x or s5x motor in your e30? These harness adapters will make the swap much easier. With this simple plug-and-play adapter, you won’t have to deal with any wiring headaches. For simplicity, the harnesses us BMW E30 Plug and Play Engine Swap Wiring Harness M50 S50 We can modify your existing M50/S50/M52/S52 wiring harness to be plug and play in the E30. This process involves removing much of the bulk of unused wires, moving the diagnostic port to the driver’s side, replacing the X20 with a C101 connector, adding in the necessary wiring for the OBC and cluster, and rewrapping all of the wiring with high temp cloth Tesa tape per the factory.