www.jec.org.uk

This may be a little long thus I apologise in advance... Shortly after purchasing my 1998 XJR in Feb this year I realised that the auto dipping mirror and the auto headlights weren't functioning... this may have been the case prior to purchase as I hadn't checked either in fact it was a couple of weeks before I actually realised it had auto headlights and mirrors even though they didn't work!! Then on checking the history file.. I noticed that back in 2009 there is a recorded failure of the auto headlights due to faulty mirror sensor... the then owner obviously decided he could live without them.

I took this to be looked at by a main dealer and they said they confirmed that they were not working and that they had checked DTC's (whatever that is) and had no fault codes and that they would need the car for more time to investigate... on discussion it was apparent it was going to cost big money in labour charges to get it investigated by the main dealer... so it was then looked at by another garage who actually changed the electrochromatic mirror for a known working one (as he had confirmed that mine was in fact not functional by trying it on the car he got the donor mirror from), even so the mirror still does not autodip and the auto lights still do not function and he too stated it would need more investigation and that it could be a long and costly job. At this point, I decided like the previous keeper that for the time being I could live without them as I can still turn the lights on manually etc.

The time of year has now come when the car gets less use and I can again think about sorting this problem... now I am not very knowledgable on vehicle electrics but am quite a practical person and was quite an accomplished mechanic back in my younger days (when unfortunately I couldn't afford Jaguars!!). As it's going to cost quite a bit to get it investigated at a garage I thought I may be able to do a little bit myself, however am somewhat apprehensive as I have such limited knowledge of Jaguars and as seen in other threads in the forum there seems to be no real info to help the diy mechanic/owner.

Could members offer any advice on this by means of a bit of detailed direction or even recommending I bite the bullet and transfer my next few months wages to a main dealer or specialist. Many thanks in advance

Ian

this is actually quite an easy job to diagnose , and rectify ,

firstly , you have a replacement mirror with the sensors within, place the stalk switch for the headlights to ' auto ' , and during daylight hours with the engine running place a finger over the sensor on the front of the mirror ( facing the windscreen ) , this will fool the sensors into thinking its darker outside than from behind , thus the auto headlights should come on,
this action should also dim the rear view mirror and the drivers door mirror , these were the standard mirrors for the auto dim function, you may also have the upgraded passenger mirror that will also dim , if it doesn't then it may not actually be a chromatic mirror , the actual mirrors are not handed and will fit either door mirror , you will need a three connector version for auto dimming functions to work ,

if non of the above actions work , then its going to be the steering column stalk, these are known to fail, a wire inside can break and reduce or completely fail certain functions,
either remove and repair the stalk, or simply replace with a known functioning one, a simple and cheap job to do DIY , just remove the screws in the column cowl , and gently remove the cowl , this will expose the stalk, it simply screws to the steering column and a multi block connector for the electrics ,

easy as that

hope this helps


BB

Thanks BB, I know that your first course of action doesn't work... as I tried this when I first discovered the problem and that was also done when we replaced the mirror with a known good one. So it's over to the Steering Column Stalk will let you know... Thanks again