Ashtray light not working (2000 W202)

[MarkyB-W202]

I've replaced the bulb but still no light .
I've looked in the mechanism on another C Class ashtray but I can't work out where the switch is.
Anybody know how it works and how to fix it?
The lighter works fine.

 

[television]

Not easy without seeing it,I do not think that there is a switch as the lamp comes on with the instrunent lamps.

if the bulbholder clips onto the lighter using sprung connectors, then the contact could be bad here, the odd third pin is normally for the bulb, do check to see if you have 12volts on this pin,and the case of the cigar lighter. if you have then the fault is local to the lamp holder