I PMed you a link to the 400/450 service manual. It should give you an idea however it should be on the transmission over or at one end of the shifter barrow. The only thing with 3+ wires coming out of it.

get i get it as well ?

Here is the 2020 450/400 wiring diagram. I would think it would be very close to the 22. I believe the pressure regulator is in the pump so no power to it has to be a relay, connector or supply issue. Check your key switch and the kill switch.

https://acrobat.adobe.com/id/urn:aaid:sc:VA6C2:c08d7ca6-d487-4944-8508-7b296d0768a6

this link doesnt work,

i have same issue 5k km 2021 manuf date, wont start then eventually a click then it starts.. sounds like relay.

i would like the manual as well