Interior Courtesy Light & Battery??

[Mike-Carter]

I have never had such a confusing/difficult car in over 43 years of driving.

My latest problem is the interior light, you know when you open a door the interior courtesy light should illuminate, it doesn't. I've tried pressing the associated button on the overhead console but nothing happens, however, all the light bulbs both back and front work when pressed individually. I just cannot fathom German logic, if there's any logic to it.

Also despite having a new starter motor fitted I still occasionally have that refusal to spin the engine then after a time it'll kick into life. I'm wondering is the main battery suspect, it may be an incorrect battery.

And there was me foolishly thinking that Italian cars were an electric nightmare.

 

[Blobcat]

The interior lights don’t come on if it’s light outside. Took me awhile and a trip around all the fuss boxes before I worked that out in my W211...

 

[Mike-Carter]

Thank you Blobcat. Guess what? Never tried it when it's dark. Job for tonight then, but surely there must be a sensor somewhere and mine is the bog standard "I'm Skint" model.

 

[Blobcat]

Normally a daylight sensor in the windscreen behind the rear view mirror

 

[Mike-Carter]

Normally a daylight sensor in the windscreen behind the rear view mirror

Thanks feller.

 

[ZZZZ]

I presume all the light on 58d circuit come on, when they should? - i.e. instrument cluster, buttons, etc?
If you have an AUTO position for your light switch, then you have a light sensor
If I remember correctly, all W169 trims had this function.

 

[Mike-Carter]

I presume all the light on 58d circuit come on, when they should? - i.e. instrument cluster, buttons, etc?
If you have an AUTO position for your light switch, then you have a light sensor
If I remember correctly, all W169 trims had this function.

Thanks GLK, yep, my car has AUTO lights, I'll try it tonight when it's dark.

 

[grahamcol]

I'd imagine that if the op temporarily covered the light sensor, the lights could be tested during daytime. Just in case he's becoming impatient.

 

[EmilysDad]

My 14 plate ML (W166) has auto lights but courtesy lights front & rear still come on in the day time .... my grand daughter tests them every week

 

[ZZZZ]

There are different setting in the menu, for interior and exterior lights and their behaviour, e.g. "follow me home" function, or interior light delay, etc, etc.

I hate to say it Mike, but one might benefit from reading a manual

 

[Mike-Carter]

There are different setting in the menu, for interior and exterior lights and their behaviour, e.g. "follow me home" function, or interior light delay, etc, etc.

I hate to say it Mike, but one might benefit from reading a manual

And pray sir, what makes you think I can read??
I just ain't gonna get lost in all that magic stuff in the wizard electronics, a new mobile phone frightens the life out of me.
My 11 year old granddaughter has shown me what my phone is capable of. Where the hell did I get off?

 

[Mike-Carter]

Gentlemen, thanks for all your advice. For the first time ever I took my car out for a dark run.............Guess what?
The interior light came on as if all by magic. One problem put to bed.

 

[daibevan]

I got caught out by that as well. The other one I got done by is the wipers not working if the door is open.

 

[M80]

I got caught out by that as well. The other one I got done by is the wipers not working if the door is open.

or if the bonnet is up.

For the intermittent starter, I would be considering the relay. I expect there is a dedicated relay in the fusebox.
More than like GLK can direct you to it. Identification by removal is less easy as yours may already inhibit the start if it is faulty.

 

[ZZZZ]

For the intermittent starter, I would be considering the relay. I expect there is a dedicated relay in the fusebox.
More than like GLK can direct you to it. Identification by removal is less easy as yours may already inhibit the start if it is faulty.

I afraid you have way too high an opinion of my electronics design abilities, or W169 technical knowledge ...
The bits I did are mostly superficial ... I'm way too lazy to learn anything new to expert level nowadays
@forrera is the best person to ask, without a doubt.

 

[M80]

While the previous Viano was working as expected I pulled relay's to identify their purpose.
The handbook was ok for the fuse designation, but was really confusing, so I created my own diagram for my centre cubby for if / when I'm trying to suss an issue in the dark, on the hoof.

Then of course there are the added clip in fuses for my little add ons.

I found it's better to create some understanding w/o the pressure of fault finding. It's all still flippin' complicated though.