Headlight Failure Whilst Driving

[E_PITT]

Driving down a busy stretch of country road last night I was rather shocked to experience brief but total front lamp failure on a few occasions.

The first time it happened my heart was in my mouth however as it repeated itself the fault started to become predicable. I worked out that it's something to do with the indicator/headlamp stalk. I have a tendancy to hover the index finger of my left hand over the headlamp stalk when driving on main beam at night so as to be able to cancel the main beams quickly for oncoming vehicles. I have noticed that a slight pressure on the stallk in the right place will kill all the lights.

I imagine it is a contact or earthing fault but I would be interested to hear if anyone else has experienced this problem.

[joejag308]

It could be a fault right at the Stalk end of the switch........a broken or loose wire or connection..........get someone with a multimeter to check the wiring down to the lights for a break or dirty contact ect ect....as long as they know how to use a multimeter it shouldnt take long....Joe

[BrianG]

Whilst it's certainly a good plan to check the wiring at the stalk through the rotating contact system in the steering column, note that the wiring does not go "all the way down to the lights" to control them. The stalk connects to the Body Processor Module (BPM), so you can only check as far as that connector.

If you have the Jaguar Heritage CD ROM it takes a bit of working out but you should be able to see from the wiring diagrams how this works. There is a composite set of contact conditions in the stalk to tell the BPM if the lights should be "off", in "park", "normal" or "auto", as well as main/dip choice and main flash functions. It may be possible when you partially press on the stalk for an indeterminate switch condition, or perhaps a bad partial contact combination to exist, which is read by the BPM as a "lights off" condition.

[joejag308]

Good comments there Brian i have had the same info in the "comments and suggestions for a while now due to the number of guys who lock themselves out of the boot and cant turn the lock with the key......a few times with the key every so often and the WD 40 in lock should save you a lot of heartache.........Joe