Fuse burns out on a W123 from 1976 when headlights are turned on

Hi.
I am trying to repair an old M230 W123 from 1976 that has a problem where the fuse burns out as soon as you turn on the lights.
I have tried to disconnect both front lights and back lights and I
have disconnected the alternator. When I switch the lights on the fuse still burnes out.
First of all, I don't have an electric diagram so I can't figure out what is connected with the light system, if anything else is plugged into that fuse.
Secondly, I am unsure what fuse should be placed in the socket, but I am guessing its a 16A - am I right?
The fusebox looks like this (each one represents a fuse):
1111111 1111111 <- this is the one burning out, the last 1 on the bottom right.
Any feedback would be greatly appreciated.
Kind regards.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I suspect a wire - somewhere - has lost its insulation and is touching the body causing a short.
If the car was in a wreck look at the wrecked area for a bare wire. Otherwise, if the parking lights are OK its much simpler, for then the problem involves only the headlights vs. the whole lighting system. Then start at each headlight and follow its power wires back, back, and back toward the headlight switch. But if the parking lights blow the fuse .......
--

2008 T.G.Lambach. Publication in any form requires prior written
permission.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You need to use a short finder to find out where the wires are shorted.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I had this problem with my 81 300td, and finally found it was a bad high beam. Took some head scratching, but I finally isolated it there.
Hope this helps!
tweaks
-- Message posted using http://www.talkaboutautos.com/group/alt.auto.mercedes / More information at http://www.talkaboutautos.com/faq.html
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@gmail.com wrote:

there is a bare wire somewhere touching earth
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.