My automatic headlights are not working. All other positions on the headlight switch perform as expected. I am not getting a "Lights Are Off" warning at the message center, so does that mean the problem is with the sensor?


Is that the sensor in the back of the rearview mirror, or is it one of those mounted behind the windshield?


Is there a test for this?

 

cfe,
Mine is basicly doing the same thing, but works most of the time. The next time you start your car and the lights don't come on (with the switch in the "Auto" position, tap the back side of the mirrow on the sensor side with your pocket knife and see if they come on. When mine doesn't come on I do that and they come on and normally work ok for awhile.
Let me know if that works for you.

Chuck 05/XK8 Conv. CF edition

 

On 4.2 cars, the sensor is mounted on the windscreen, and looks like this.





I have the opposite problem to you, the auto setting wants to keep the lights on all the time. I am just living with it, but the "lights off" message on the dash in daylight hours is a persistent niggle.

 

Thanks, guys. Yesterday (daytime), I fired up the car to run an errand and the headlights came on (yeah!) because it was set to "auto" and the car was inside. (This is what normally happens with my other car.) When I returned home later and pulled in the lights did not pop on as I expected, so the problem is intermittent.


This might be a clue. Before I started the car I was looking at the rear view mirror and noticed that the two piece cover between it an the windshield was loose, and I fiddled (yes, I am Southern) with that some to snug the pieces together. I also noticed that with the key turned on and with me fiddling with those cover pieces the automatic wipers would swipe. I'm starting to think there is a wiring issue in that region.


I had to head out of town right after, so have not had a chance to explore further.

 

I have discovered that the problem is in the wiring where it plugs in at the windshield. I can tap the mirror or the black plastic shroud and make the lights and wipers come on and off. Wouldn't that be cool if it were meant to be a feature? I popped the shroud off but could not find a frayed, loose, or raw wire. Wiggling the connector or the wires makes things go on and off. It's all working now. We'll see what happens when I go over a bump.

 

Thanks, this thread help me solve my "Lights Are Off" problem on my 2005 xk8 4.2. I my case when I removed the mirror I found the circuit board that holds the sensor (see picture posted by RaceDiagnostics below) had fallen out of position. I placed it back in to position and now it working correctly.
Thanks for your help.

 

On my 03 the sensor is part of the Mirror assembly and not attached to the window, only the rain sensor is attached to the window on my 03.