So I changed the OVP, and still no ABS

Further examination has revealed that ABS functions if I bypass the OVP, with the 12V supply from the ignition.
The big thing is, there is no 12V to pin 30, which I believe is the main supply to the relay.
I opened the socket and can see the big brown wire is connected ok, but has no power.

Any ideas where this wire gets it's power from? All the fuses have been replaced. and none of them seemed relevant anyway.

Or would it be better to install a new 12V supply to that pin?