Oil pressure sender (gauge) question

[robbyj]

To anyone who has done this before or knows how:

This is the diagram that came with my oil pressure gauge, and i have a couple of questions. I am fairly good with the wiring side of things, wiring this all up wont bug me, the small mechanical side will.

On the attached pic you'll see the diagram sent with the gauge on how to wire it up.

Question 1.
Where the 'Red' wire is to run the the ignition switch, can i just run this to the head unit power supply, as the h/u turns on when the ignition is turned

And according to the diagram is it asking to run it to the ignition switch or then onto the battery.. or would this not be required.

Question 2.
Where do i attach the oil pressure sender unit to (dumb question it may seem, but i dont have any idea where im ment to put it so it can 'read' the oil pressure.

Sorry about the quality of the pic, but u get the idea