Mercedes Benz Atego 1222, built in 2009, manual gearbox, crane tipper. The following problem: reversing headlights without function We have already checked the usual things. We pull the relay K7 (reversing headlight) at the top of the basic module and give power to 30 and 31 burn the return headlights. Therefore, no cable break to the rear. The relay is new, also we have changed the basic module for precautionary reasons. All fuses are inside. r with the Star Diagnosis, the return light will not happen. It is also funny that the Star Diagnosis does not recognize a GM. Otherwise everything works on the truck, we can also control everything else with the Star Diagnosis. According to our knowledge, the relay is controlled via the basic module, this should happen if the switch on the gearbox gives signal. (cable color from below: black/green and black/yellow with red stripes. Both cables go up into different plugs. We are with the Lat One at the end.