Electrical System Diagnostic Plug / Test Port

[Doob]

RE: 1971 Kombi electrical system.
For some years now I have stared at the electrical Diagnostic Plug/Test Port in my engine bay and thought this could be useful  
Possibly make up a panel for remote engine start, and basic instrumentation to tie into this Diagnostic Plug.
Might make engine tune ups and trouble shooting easier ?   
From what I can see my fixed plug in the engine bay still has all the original wiring in place.

I imagine the original male pin socket that plugs into this fixed female receptacle plug is as rare as rocking horse poo now? 

Just curious - has anyone ever tried to use this Diagnostic Plug?  Has anyone ever made up a DIY male pin socket to fit?

Just for background info on this Diagnostic Plug, some light bedtime reading can be found within these links 
http://www.speedyjim.net/htm/plug.htm
https://www.thesamba.com/vw/forum/viewto...p?t=720303

[Barry]

I’d contact Les. 
Reckon he would be the only one that knows the answe. 

As far as I know it’s useless

[syncro]

Just curious - has anyone ever tried to use this Diagnostic Plug?  Has anyone ever made up a DIY male pin socket to fit?

I just used the one on my '75 Beetle the other day. Made up some cables to connect to charge the battery (Terminal 30 & 31). Also handy for a test light or timing light. It doesn't appear to have all of the available cabling installed. You could use it for turning on the ignition (15), remote starting (50) or setting the static timing if the wiring is there (13).

In 50 years, I have only seen one plug. A lot of the VW dealers had the blue and gray box but it was empty and only for show. I have heard that there were only 2 complete machines in Australia, One at LNC in Ryde (for loan & training) and one at Muller & Muller, Lakemba.

I'll have to have a go at making my own plug.

[grumble]

I’d contact Les. 
Reckon he would be the only one that knows the answe. 

As far as I know it’s useless

Barry the diagnostic plug actually had a connector that we connected when servicing and allowed us to test various circuits including the dwell, set the timing etc. I left the dealership to work for the service manager at a new workshop at Tuncurry specialising in electronic tuning and wheel aligning shortly after the unit was fitted so I never had a lot to do with it. If you use a test light you can work out which terminals belong to the tail lights, brake lights, dwell etc. I am certain that the designation is in one of the manuals but I would not call it useless.

[syncro]

I can't really see much accuracy with some of the functions once the wiring ages. The compression was tested by the voltage drop on the starter. The battery was tested by a 6 volt terminal in the centre of the battery. How long since anyone has seen a battery with the test terminal? 

Note that not all of the terminals are connected. Mine is similar to this one.

[Mordred]

I can tell you there is one wire that goes from the plug to the 8 way connector above the fusebox. (i think blue or blue green from memory and may have been originally for the rear defrost as in the diagram 5).  You can link it to the one from the coil 13 and then extend from the fusebox connector (it is the wire that ends at that connector and is blank on the other side) and use it for a tacho on the dash or you might be able to use it for a pressure or temp sender.  Works a treat.

Adrian