Thread: Brake light/fog light trouble

G'day folks!
I need some advice regarding the following problem with the brake and fog lights. The truck is a 2001 Defender:
When hitting the brakes the fog light warning lamp in the instrument panel flashes up and then glows dimly. Releasing the brakes extinguishes the warning light. Both brake lights (LHS & RHS) are working fine, as are the tail lights and reversing lights. The fog light doesn't work, though. When checking the voltage at the bulb connector I only get a reading of about 11V, and this is on either LHS or RHS (there is wiring for fog and reversing lights on either side). When connecting the bulb to the RHS fog light, the fuse blows, not so on the left, but, as stated, the bulb won't light on either.

Am I correct in assuming an earthing fault? Where do I have to start looking? So far I have followed the wires as closely as possible but could not detect anything abnormal. Anyone here who knows the relevant earthing points and their location?

I am grateful for any advice as the truck's annual RWC inspection is looming and I don't want to risk a notice...
Ta in advance!
Cheers

Thanks, folks!
I have cleaned and checked the trailer socket. Something has happened as the warning light in the instrument panel doesn't come on anymore. Everything works as it should, except when I try to turn on the rear fog light the fuse blows. I disconnected the tow hook wiring loom but the problem persists.
As I honestly don't have a clue what the cause for the troubles are I am grateful for any advice...
Cheers