When i bought my car it had an aftermarket boost guage but
it wasnt screwed in right so i took it off also wondering why there was another one. But then 12mths later i realised it had a 1 bar spring installed!
So im now trying to get it working again...

Theres a tube coming inbetween the seats that goes into the rear of the guage
and two wires coming out under the dash (theres +,- terminals on the back)

Am i right thinking the wires are just for illumination and the pressure from the tube changes the reading?
Also ive tried to connect it up but it doesnt work, ive tried seeing if air is coming out of the tube under boost- but no luck. should i expect this?

Also does anyone have an idea where the tube connects to to get a reading of the turbo pressure?

Cheers alot! Miles