1. Rear fog light should cut out when trailer plug is inserted. The wiring was straightforward except one diag that suggested you must cut the wire in the car’s loom to the rear fog light and connect the grey wire from the trailer relay unit. Finding the wire was easy with a pin and a meter, I cut it and then had a choice of which end of the cut yellow to join the grey to. The diagram was no help as there is only a picture of some scissors and a wire, no schematic to show the actual circuit! However connecting it to either end of the cut yellow did not allow the rear fog to come on regardless of whether the trailer plug was inserted of not. Reconnecting the yellow allowed the light to work as normal.
I can hear the relay click inside the unit when the rear fog is switched on regardless of whether the trailer plug is in or out, because there is no microswitch in the socket itself I assumed the unit must sense the current going to the rear trailer lights and switch the rear fog off accordingly.
Does anyone know how this circuit is meant to work?
2. Switching off the Rear parking sensors. The car had Nissan rear parking sensors fitted already, they don’t trigger with just the towing ball but are on constantly when a trailer is hitched and reverse is selected. My understanding is that the standard Nissan trailer wiring should disable the sensors when the trailer is connected. The rear sensors are controlled by a Nissan unit called ‘RPS20’ apart from the sensor wires it has a black (to earth), red (joined to the reversing light wire in loom) and 2x Blue (not connected)
Does anyone know how this how this can be wired to be ‘switched off’ when towing?
Hoping someone can help as reversing with a trailer is hard enough without the rear parking sensors screaming
- Alan
