S3 8l AMK Gauges install

[S3Powerxz]

Hello.
I have Audi S3 8l AMK engine. I bought 3 gauges: Boost gauge, volt meter and oil pressure.
Can someone tell me how to wire it so the gauges will dim when i use the dimmer?
Also can you give me diagram for headlight switch?

 

[IPG]

There’s a grey w/blue stripe wire at the dimmer. Tee the positive into that.

 

[S3Powerxz]

Can i use 75x terminal for ground?
Or it was other relay for ground threre?
I just don't want to modify too much stock wiring.

 

[IPG]

Why not. No one sees it...

Ground to a ground. Many points under the dash. Look for where brown wires gather.

75x is powered... as well as the other points under there don’t ground to any of those points under the relay box.

 

[S3Powerxz]

Ok. Thank you for the help.
One last question.

If i wire the positive to grey with blue strip on the dimmer the gauge will turn on with the lights, right? Not when the key is on accessory position?

 

[IPG]

It’ll go on when you turn the headlights on.

 

[S3Powerxz]

Thank you for the help!
You are one of the "golden" members in this forum for me.

 

[IPG]

Not a problem.

It’s how o have my boost and oil pressure gauge wired up. So it should all work the way you want it to

 

[S3Powerxz]

About oil pressure gauge.

Where i have to put the sensor?
On the free allen bolt on top of oil cooler or somewhere else?

Also what readings should i see on stock AMK engine?

 

[hendo#1]

I put my pressure sender there, yes.

My BAM engine on 5w-40 oil will read 80 - 90psi (cold oil) at idle.

Around 20 - 30psi on a warm oil idle.

Cruising is obviously dependant on RPM, around 60 - 70psi at 80mph IIRC.