Early Plus 2 horn relay

[bill griffiths]

The early Plus two wiring diagram does not identify the horn relay terminals to which the purple/black (Earth from stalk) the purple/white (+) and the unspecified wire (light green I suspect) to the horn compressor are attached.
There is little help, at least to me, from the terminal markings seen in

the picture.
I removed the relay for testing and found that either it is internally deranged or I am missing something important!
Any thoughts?
Regards
Bill

[Craven]

This may be of some help.