I just finished working with an owner on jaguar forum. He faced the common question: my auto headlights do not turn on. Is my mirror broken (it houses the opto Electric sensor), or is the switch faulty.

Turns out that if you pull the overhead console down and expose the wire harness from the mirror, you will bypass the mirror sensor if you ground the yellow blue wire. Iow, if you do this and the lights work normally [switch=auto; ignition on] you proved the fault is in the mirror.

I am posting this for all of our future reference. My thanks to Pete on the other forum. John