Ambient Light Sensor?
 

I know that this sensor is located some where on/in the rear view mirror but I'm not sure exactly where. Can this sensor be used with an aftermarket mirror or is there a way to locate the sensor independent of the mirror? Thanks,

Mark

Mark,

There was a recent thread around rear view mirror issues:

https://www.jaguarforums.com/forum/x...ht=rear+mirror

See Keith Westra's post No 11 for photos of the sensor and connector.

Graham

That post mostly shows the rain sensor. The light sensor is on the rear of the mirror itself.

I will post this picture as you can somewhat see it. The light sensor is in the hole on the left side of the picture, near the mounting point. The dial in the center adjusts how dark it has to be before the lights turn on.
https://img222.imageshack.us/img222/...attachment.jpg


I'm not sure of any way to remove it from the mirror and I don't know if you can get an aftermarket mirror with a light sensor or not.

What exactly do you want to do, Mark? Is there a replacement mirror you prefer, or is yours damaged in some way?

My current morror is fine; this is related to my other post on the blind spot monitor. I found a mirror online (Amazon.com: Auto-Dimming Rear View Mirror with Built-In Monitor, Model# 50-GENK242: Home Improvement) but I'd like not to loose the auto head lights feature. If I could somehow relocate the sensor, then I'd be set.

mark

I was just washing mine today and thought I saw the ambient light sensor on the back of the mirror mount....an irregular rectangle shape with an open depression.....or is it somewhere else...on top of the dash for instance?

My auto on lights don't seem to work, I turn the steering wheel knob behind the steering wheel to auto but still have to turn the lights on with the light stalk control.

Not a big deal...and no doubt I am doing something wrong....I really should read the whole manual one of these days......

cheers,

jj

The stalk should be set to auto. The knob on the steering wheel is for the automatic tilt/telescoping wheel. The light sensor is in that hole in the back of the mirror as you guessed. The sensor on the dash is a heat sensor to help the climate control system account for solar heat gain.

Mark, Since you are going to be doing some wiring anyway, I wonder if something like this would work for you:
LAND ROVER P38 AUTO HEADLIGHT HEADLAMP SUN LIGHT SENSOR | eBay

It just might be the solution and it cheap enough as well. I'll have to do some checking ad see it it will work. Thanks,

Mark

KW;

Thanks, makes perfect sense.

Will give it a go on the stalk control though my recollection is that didn't work....but maybe I was too impatient.

cheers,

jj

There is also a knob on the back of the mirror to adjust how dark it has to be before the lights come on. I keep mine set at the brightest level so my lights come on as soon as possible and its just about perfect for me.

Keith,

The design has been changed on the 4.2's. No knob on the mirror now and a much bulkier pack for the ambient and rain sensors, masked by a shaded area on the windscreen:

Attachment 17565

The marks are rain on the screen - not on the seats!

Graham

I have looked at mine but don't see any indication as to which way makes the lights come on when it is lighter out. Which way does the knob need to be turned? Lights are working fine but like you I would like them to come on as early as possible when it is lighter out.

Thanks

Hey G;

Great photo that is it exactly.

So on the 4.2's you have to adjust the auto on for the lights exactly how???

cheers,

jj

jj,

There's no adjustment available on the 4.2's, it's now a 'predetermined level'.

Just set the rotary collar on the light switch to AUTO. When the light fades to the predetermined level Jaguar have decided justifies lights, sidelights and headlights automatically switch on and the sidelight icon in the instrument panel illuminates. As it gets lighter, the lights automatically switch off again. Recommendation is to leave the switch in AUTO but you can always override it using the rotary switch.

Graham

I went to check this for you, and I must have fiddled with my knob since I don't seem to have it cranked to one extreme anymore. I'll have to readjust it sometime. What I did the first time is to find a time when there was partial light and mess with the knob. If you can get just the right light conditions you can have the lights turn on at one extreme and off on the other and then fine tune from there.

Good to know. Maybe Mark can separate the light sensor from his mirror then.

While trying not to be dense, I'm still not certain if the ambient light sensor is in the mirror or in the bracket for the mirror that is attached to the windshield. I also verified no knob but I do have a push button on the bottom of the mirror that says "auto" and causes a little green light to illuminate when depressed. What does this button do? If the the ambient light sensor is in the mirror, I can but a mirror from Coventry West for $175 and take out the ambient light sensor and relocate it some place. However, if the ambient light sensor is part of the bracket on the windshield, I may be able to find a way to attach the new mirror to the old bracket, leaving the sensor untouched.

Mark

Mark,

The button is for the mirror dimming function - not the headlights.

When set to AUTO, the mirror darkens when headlights approach from behind to reduce the glare. It's very effective.

You've probably read about occasional problems with gel leaking from rearview mirrors? This is the photo sensitive gel used to darken the mirror.

Graham

Thanks G.

jj