The fact that none of the rear lights are working and that you've checked the fuses would suggest a wiring problem. You can do a couple of things. I would check the earth first - which may be contained within a junction box mounted somewhere on the chassis towards the rear of the vehicle. These should be waterproof but often aren't so may be suffering from corrosion. Take the box off and clean all the connections - especailly where the earth contacts with the chassis). If that appears OK, check all the remaining connectors. If your vehicle has been altered since manufacure (in to a horsebox for instance) then the original wiring loom will have been cut in to as part of that alteration - the connectors where the loom was cut in to may need some TLC if it hasn't been done very well or was done some time ago. Check ALL remaining connections for the rear lights, including inside the light clusters themselves. And if you haven't already, check the bulbs too! Take your time and follow it all through logically.
Sean, June 2010
