As part of an ongoing saga I've been trying to get the auto lights to work on my XK8 for as long as I've owned it. Other events of course take priority but every now and then I go back to it.. I've looked for broken wires and loose connectors wiggled light switch stalk etc but not a flicker.
Last week I jumped in the car late at night and set off on my journey home. After a while I thought "I didn't switch the lights on " but they were on! What an Idiot! I didn't realise the engine had to be running and assumed that they were the same as my X350 and worked with just the ignition switched on.
Next day I covered the sensor with some tape and drove around as normal. It seems that the auto lights come on sometimes when the sensor is covered but always go off when the tape is removed.
Anyone think it's a faulty sensor? If so I'll continue to switch off and on manually.
Thanks

 

Might be a faulty sensor connection too. Pull the speaker out from your dash - the connector can accessed from there.

 

Thanks Jim.
Are you referring to the speaker in the overhead console, the one with the interior lights? I'm not sure how to get that console off without breaking something, it seems to be well secured. You could be in the right area because today with the sensor covered the lights didn't come on, I touched the mirror and on they came.
Pete

 

No,no. That's Not a speaker in the overhead. It's a position sensor for the pax seat air bag. I'm talking about the speaker grill on top of the dashboard outside of the sun light sensor . It just pries out easily. The sun sensor connector
Is beneath.

 

The sensor that I have taped over is on the back of the mirror and it seems to be sort of controlling the lights when it feels like it. I thought the one on the dashboard was for the heating system. These cars are full of surprises. More investigation required.
Thanks for the input

 

OK. This Is good. You're on the right track now . That little black dome on the dash is your sunlight sensor. The HVAC sensor is behind the little grill in front of your right knee.