You need to connect a drive relay. The controller has a dedicated output for this. Look under the bonnet for a harness with a few free wires. The brown one is the output circuit for the relay, otherwise you'll have to open the controller plug and tap off it. If you are lucky, the parameter setting will be set to drive the relay when reverse is selected otherwise you can change the parameter setting with truckdoctor. The relay is only activated when the forward/reverse lever is put in reverse AND the accelerator is pressed. The relay can be installed under the cover on top the bonnet.