boost gauge not working

[istoo]

hello, i bought a urS4 recently and the boost gauge was working until last week now nothing. its is boosting but the gauge isn't reading either the digital one or the aftermarket one on the door pillar.

I am all new to this, how do i trace it back and fix?

[GazzaG60]

sounds like they are t pieced into the same line so the line has been dislodged.

have a look for a line at the back of the clocks or boost gauge and follow it back. check vac connectnios under bonnet