Where is the Light Monitoring Unit on 500SL

[Optimist]

I have a 1988 500SL - (107type) and keep getting intermitent problems with brake and rear lights.

Looking at the wireing diagram I suspect that the problem is something to do with the Light Monitoring Unit.

My initial problem, is where is this located.

Thanks in advance for your help.

 

[Optimist]

ttt