Dome light trouble shooting?

tvnews

New member
Hello,

I'm looking for a diagram / electrical schematic for my 2013 crew cab 170 wb. I need to troubleshoot the front cab dome light. The light has stopped coming on when I open the door. However I can manually turn it on. I checked with a volt meter and the brown/green wire does not provide a ground any more. I have been poking around with my volt meter and I do see about 10 volts ref ground on the brown/green wire. I assume this is coming from a switching transistor MB must use? I do see the dash lights come on when I open the door so the door does seem to be sending some type of signal when it opens.

Btw, I checked the fuses in the panel under the dash on the drivers side. All the fuses look good except for fuse #1. That fuse does not seem to have power At all nor any power with engine on or off. Any idea what this fuse powers?

Dean
 

lindenengineering

Well-known member
The SAM module grounds the circuit by ground switching.
Most likely you will need to find the grounding wire at the SAM (body module) and ground it down. If it all works its most likely a fault in the SAM.

(Not quite as tricky as Sam Weller of Pickwick Papers fame! )
Dennis
 

tvnews

New member
The SAM module grounds the circuit by ground switching.
Most likely you will need to find the grounding wire at the SAM (body module) and ground it down. If it all works its most likely a fault in the SAM.

(Not quite as tricky as Sam Weller of Pickwick Papers fame! )
Dennis
Thanks, I never got a chance to tackle this. But I do need to now. Were can I locate the SAM unit?

Thanks again
 

pfflyer

Active member
I hate to point out something obvious but you do know the switch that turns it on has 2 more settings. Always off and on when the doors are open and also I think when you unlock the doors with the key fob. If you are already aware of that then I have nothing to offer except it could be a bad switch.
 

Picoscope

New member
The SAM module grounds the circuit by ground switching.

Most likely you will need to find the grounding wire at the SAM (body module) and ground it down. If it all works its most likely a fault in the SAM.



(Not quite as tricky as Sam Weller of Pickwick Papers fame! )

Dennis


Software update for SAM at dealer will repair the dome lamp issue.


Sent from my iPhone using Tapatalk
 

Schumannj

New member
The front Sam is located under the dash behind the obd port. The fuses that are in this circuit are 17 and 19. I've delt with a lot of lighting issues on these. A big issue is the rear bulb carriers will short themselves out the positive bulb clamp with touch the negative and will pop either one or all bulbs.
 

Mickyfin

New member
Hello,

I'm looking for a diagram / electrical schematic for my 2013 crew cab 170 wb. I need to troubleshoot the front cab dome light. The light has stopped coming on when I open the door. However I can manually turn it on. I checked with a volt meter and the brown/green wire does not provide a ground any more. I have been poking around with my volt meter and I do see about 10 volts ref ground on the brown/green wire. I assume this is coming from a switching transistor MB must use? I do see the dash lights come on when I open the door so the door does seem to be sending some type of signal when it opens.

Btw, I checked the fuses in the panel under the dash on the drivers side. All the fuses look good except for fuse #1. That fuse does not seem to have power At all nor any power with engine on or off. Any idea what this fuse powers?

Dean
This is the exact same issue I'm experiencing, did you ever manage to sort it out? I know its an old thread, but worth asking.
 

Mickyfin

New member
Ok, an update on my cabin interior light issue.

I have checked absolutely everything in the system and cannot find any issues, which leads me to believe, according to what I have read within the forums, is that I need the dealer to reset the system, or there could be an option in the dash computer to switch it on>?

I have a suitable OBDII https://www.ebay.co.uk/itm/Autel-Ma...ine/322895066318?_trksid=p2485497.m4902.l9144 which is able to clear airbag, and SRS faults, does anyone know if this device can also clear the issue relating to my interior light not coming on when either of the front doors are opened?

Summary..

When drivers door is opened, the dash lights come on.
When key is in the ignition, the dash sounds when drivers door opens
When passenger door is opened, dash light do not come on.
I can switch on the cabin dome light via the toggle switch (brand new OEM light purchased).

Cargo area lights work 100% correctly.

My dash is that is the 2011 model without sterling wheel controls, one that looks like this....



Does anyone know, if I have the option to able/disable dome light via the control panel in the centre via any of the four push buttons?
 

Mickyfin

New member
Just read this via another forums..

Check the bulb in your cigarette lighter, if this bulb is gone it affects the circuit. Hence lights won't come on when doors are opened.
Would this be true with Sprinters?
 

sparkplug

Member
Micky - I still think could be the switch in the door lock which senses when the door is open.

I had *exactly* the same problem (apart from mine was the driver's door). Mine was easy to test, because the warning sound didn't come on if I opened the driver's door with the lights on.

Here's something which might be worth trying.

Put the key in position 3 (all lights come on for a few seconds and then go out) or just start the van so the engine is running.

Then open the passenger door.

Do you get this light come on on your instrument panel?
https://i.postimg.cc/qRwtX5XD/dooropen.jpg

If the answer is 'no' then the van doesn't know you've opened the door and the problem is in your door sensor which is buried somewhere inside the lock mechanism.

I have zero experience of using diagnostic tools, maybe someone knows if there is a more accurate way of finding out if my theory is correct using one of those?
 

Mickyfin

New member
Hi mate, yes, my dash shows door open light on the dash whilst engine is running, and also lights up when I open either of the front doors.

With headlights on, when I open the drivers door, the dash sounds off the ding ding, so it knows the door is opening, I did have a play with the lock mech, but didn't do anything.

Let me pop out and test again with engine running in case I'm wrong. Best to triple check then we are on the same page.
 
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Mickyfin

New member
Right, an update, and sanity check lol

With engine running, the door open light does indeed illuminate when I open either of the front doors.

Being in Finland, you have to use your daytime running lights all the time, and as such, my van has been wired so the headlights automatically come on when the engine is started, even though the headlight switch is in the "0" position.

Switching the headlights to side lights, this switches off the normal beam, and only lights the side lights.

When I switch the switch to normal beam, it switches off the headlights, this is something I have noticed with a few vehicles we have owned there, they all do the same, for example, you cannot use your main beam unless you put the switch into normal beam position.

Talk about confusing, but this is due to the law here in Finland.
 

sparkplug

Member
Hmm - that's frustrating.

Do you have access to another dome light which you know is working (or another Sprinter / Crafter you can try installing your dome light into)?

That would confirm if the fault is in the dome light itself or in the connection to it.

I would offer to post you mine - but I suspect the postage costs to send it to Finland and back to the UK would make it impractical.
 

Burkilimo

New member
Micky - I still think could be the switch in the door lock which senses when the door is open.

I had *exactly* the same problem (apart from mine was the driver's door). Mine was easy to test, because the warning sound didn't come on if I opened the driver's door with the lights on.

Here's something which might be worth trying.

Put the key in position 3 (all lights come on for a few seconds and then go out) or just start the van so the engine is running.

Then open the passenger door.

Do you get this light come on on your instrument panel?
https://i.postimg.cc/qRwtX5XD/dooropen.jpg

If the answer is 'no' then the van doesn't know you've opened the door and the problem is in your door sensor which is buried somewhere inside the lock mechanism.

I have zero experience of using diagnostic tools, maybe someone knows if there is a more accurate way of finding out if my theory is correct using one of those?
Spray a healthy dose of wd40 into the driver side lock and then use compressed air to blow it all out. That makes the door sensor work sometimes
 

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