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Pete
Pete, Mercedes Mechanic
Category: Mercedes
Satisfied Customers: 28785
Experience:  Over 15 years experience as a Mercedes dealer technician
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The rear dome light continues to flicker after the 8sec turn

Customer Question

The rear dome light continues to flicker after the 8sec turn of period
JA: Have you checked the vehicle's manual for this?
Customer: Yes, it mentioned nothing about that problrm
JA: What is the model/year of your Mercedes?
Customer: 2003 E500
JA: Are you fixing your E500 yourself? What have you tried so far?
Customer: I removed the rear dome light and looked at the circuit for dirt or corrosion.
JA: Anything else you want the mechanic to know before I connect you?
Customer: that is all the info I have so far.
Submitted: 10 months ago.
Category: Mercedes
Expert:  Pete replied 10 months ago.

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

Try pulling on each rear door to pull it in tighter to the closed position and see if the dome then stops flickering.If you pull on one of the rear doors to the closed position tighter and the light stops flickering this can indicate a fault with that doors dome light switch needing replaced.I have seen several of these switches fail in the past before and cause this issue here needing replaced.If this is or was already checked and found o.k. let me know so we can continue.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Customer: replied 10 months ago.
Hello Pete,
Thanks for your expert advise and response. I have tried everything to make the rear dome light stop flashing. I think that if it was the door switches/sensors it would trigger the 8 sec timer then the light would go on then time out after 8sec. When you enter the car through the front door all the lights comes on then the front goes out them the rear stays on for 8sec then start flashing.
Expert:  Pete replied 10 months ago.

Is this a consistent off and on flash at the same time interval or inconsistent?

Let me know so we can continue,thanks Pete.

Customer: replied 10 months ago.
Pete, it seems that the flashing is random, it does it some time and sometime it works ok. I had taken it to the dealer some time ago and they could not reproduce it so they told me that it was the control module and changed it , but the problem came right back. This happens sometimes by it self when the cal is turned off and the alarm is on. Howerev, when the car is off and the alarm is on the flickering does not trip the alarm at all. That is also another reason why I don't thing it's the actual door switch.
Expert:  Pete replied 10 months ago.

Try toggling this rear dome light switch off and on a few times in case the contacts are sticking in it causing this issue.This switch is located in the over head control module seen with the red arrow below.If this does not work and the alarm is not going off with this fault here this would lead me to believe the over head control module (where the red arrow is pointing to is the control module/ecu) is faulty internally causing the rear lights to flicker off and on like this here.I have had to replace and program some of these before for electrical faults similar to this.It is the entire panel that you see above the rear view mirror assembly.

https://www.dropbox.com/s/ynww6vloqwtqmk4/d-11-25.gif?dl=0

Let me know if you need anything else and feel free to rate my help here as this is how I receive credit for my time.Your 5 star rating is appreciated

Thanks Pete

Customer: replied 9 months ago.
Hello Pete, sorry for the delay. I had some medical issues that I had to deal with. The last time we spoke, you ask me to shake the switch noted on your diagram. I tried what you said and it did not seem to make a difference. One thing that I noticed, is that the light only flickers during the night or days that are over cast. It appears that a sensor detecting darkness. The sensor is working OK. Also, how do you remove the front dome light assembly? Is it the same way you remove the rear??
Expert:  Pete replied 9 months ago.

I dont see this as a light sensor issue here.This sounds more like the over head control module itself at fault needing replaced.I have seen the over head control module cause this type of fault here before needing replaced.This will have to be setup and programmed after replacement.It is a good idea to have the fault codes checked/read out first to see what codes are set and then those codes can be diagnosed and repaired to help resolve this but I do suspect since it flickers this sounds like an electrical fault in the over head control module itself.

Let me know if you need anything else and feel free to rate my help here as this is how I receive credit for my time.Your 5 star rating is appreciated

Thanks Pete

Customer: replied 9 months ago.
Hello Peter, thanks for responding to my question. However, I am not sure which light which control you're referring to is it the one in the rear or the one in Front. How do you remove the front domelight assembly.
Expert:  Pete replied 9 months ago.

This would be the front control assembly which is an ecu/computer of its own built into the front dome lamp assembly.

https://www.dropbox.com/s/oung4w8cvw1e4ye/o-12-05.gif?dl=0

https://www.dropbox.com/s/202ykv3f1zon7sa/om-12-05.gif?dl=0

https://www.dropbox.com/s/9mxncquoumx18z0/rom-12-05.gif?dl=0

1 Disconnect ground cable of battery
2 Pry off rain/light sensor covering (1) with mounting wedge toward bottom and remove

See "Special Tools" given below.

3 Unclip mirror base cover (2) from overhead control panel control module (N70)
4 Disconnect electrical connector (6) from rain/light sensor
5 Slacken interior rearview mirror unit (A67) through lateral swinging at the mirror base and simultaneous pulling toward bottom out of the mirror mount

NOTE:
- Let interior rearview mirror unit (A67) hang at wiring harness.
- Installation:Press spring shackle bolt (5) together with pliers (arrow) and allow retainer to latch.Ensure that wiring harness is routed properly.

6 Release overhead control panel control module (N70) at front by pressing pushbuttons (3)
7 Release overhead control panel control module (N70) at rear by pushing off at side using mounting wedge

See "Special Tools" given below.

8 Unplug electrical connectors at electrical connections (4) of overhead control panel control module (N70) and remove overhead control panel control module (N70)

CAUTION: Carefully remove overhead control pane control module (N70), otherwise the flat strip lines could be damaged.

NOTE:
- The number of electrical connectors is dependent on the vehicle equipment.
- Installation:Ensure that wiring harness are routed correctly.

9 Disconnect electrical connectors of the interior rearview mirror unit (A67) from the overhead control panel control module (N70) and remove interior rearview mirror unit (A67)
10 Install in the reverse order
11 Perform function check

Special Tools

https://www.dropbox.com/s/uiacncfn96izns6/st-12-05.gif?dl=0

I would have this further checked with having codes read out with a dealers sds machine plugged into your model or equivalent to see if any codes are set in this over head control module.

Thanks Pete