That puzzling moment when you realize the previous owner was a sparky.... I believe this was to turn a Sub Amp on...
Finally got around to wiring in a relay for the W2A pump, no more jamming wires into the battery terminals every day. Popped the plastic out with a flat screwdriver, the silver ring comes out easy and then the black piece around the gear stick is separate. Its little harder to pop the clips on this bit but its not fragile. Then the Coin holder/lighter part pulls out towards the gear stick, easy peasy.
A little sketch of how it was wired
This means the W2A pump comes on when i turn the key to ACC - Prob's not going to be ideal in the long run as it would be best to trigger the relay when key is at ON position. But for now to save me from jamming wires in and out and potentially forgetting to turn the pump ON before i drive, it'll do.