I made my own. Excuse my dodgy microsoft paint drawing
Easy way to remember the layout for a 4 pin relay. What goes in to the "T" comes out of the "T". The two other terminals connect them.
Use 17amp (or whatever your pump is rated at) wire for the power from the battery to the relay and to the pump. Also the earth from the pump to the chassis needs to be 17amp.
The wire from the OEM pump relay and the earth for relay pin 85 can be small gauge 8amp as they don't carry large currents.
I fitted my relay into the OEM relay board and it looks factory, then run the large wire to the pump with the existing wiring loom.
To get the correct wire for relay pin 86, find the relay board (prob under the steering column). Turn on the ignition and feel for the relay that clicks, but then clicks off again as the pump runs and turns off for a few seconds. Behind this relay is a wire that will pulse +12v positive and then stay constantly positive when the engine is running. It sould also remain positive when cranking the engine. Use a test light or multimeter to determine. If I remember, usually on VAG cars it is yellow with a red strip but I could be wrong, so test it.
