My 52 plate Mondeo TDCi 115 won't start. There are no clicking noises or anything when I turn the key so I think it's something electrical rather than mechanical. It's failed before when a connection on a wire going to the motor broke but that wire looks OK this time.
I tried turning the lights on to see if they looked dim, but only the sidelights would come on, not the headlights. I thought they looked a bit dim, but I'm not at all sure. I'm pretty sure the headlights were both working OK before, so I think it's too much of a coincidence that they would both happen to fail at the same time as the starter.
Is there something that would cause the starter and headlights to be disabled at the same time? A common fuse or relay, or perhaps if the system detects a flat battery it disables high drain components to protect it from completely draining? Or maybe the lights simply won't work with the engine off and/or door open?
It seemed to be turning over normally for the first few days of the cold spell, but I believe cold can kill batteries rather abruptly and the car's last few journeys were very short.