Occasionally headlights flicker on/off (with either manual on or auto switch.)

I had this, and it finally culminated in all headlights going off for about 2 seconds on a very dark road on a moonless night two years ago . The road was very twisty too ! Those two seconds can seem like eternity when your doing 40 mph !!

After that little incident I finally bit the bullet and sorted the job out. I had previously been troubled by the lights coming on in daylight on auto setting in bright sunlight and the satnav screen darkening. Study of the wiring diagram showed that there are only two moving parts between your finger and the headlights, (1) the lighting switch on the steering wheel binnacle, and (2) the headlamp relay.

In the end, a new lighting switch cured the problem. Study of the old switch showed somebody had tried to fiddle with it, and I believe these switches have been a regular cause of trouble. They cost about £125

Check its not the park lamps

If you have LED lamps installed the park lamps occasionally flicker or pulse on/off after you shutdown the car

As best i could tell the reason is the lower resistance of the led lamps is messing with the FEM. Even the canbus lamps do this

I did some testing and added a 150ohlm resistor inline which seemed to cure the problem but never got around to installing them permanently

When it happens I just use the remote to turon on the off for the headlamps

Cheers
34by151