Have Mercedes Questions? Ask a Mechanic for Answers ASAP
Hello and thank you for your question,Yes there are two wiring diagram which cover all the interior lamp circuit. See them both in the link below. Have a look and see if this is what you are needing.https://dl.dropboxusercontent.com/u/104923897/Interior%20lamp%20Dec%2017.pdfhttps://dl.dropboxusercontent.com/u/104923897/Interior%20lamp%20%232%20Dec%2017.pdf
I have enclosed the cluster removal steps that Mercedes offers.https://dl.dropboxusercontent.com/u/104923897/cluster%20Dec%2017.pdf
I think the cluster has to come out to get to the connector.
Well you are going to need to trace the circuit to find the cause. Thats what I would so if I was there.
Yes you should be able to access from underneath if you have the right size hands.
No problem, Im off today but will return on Monday if need be.