4agze --> SuperCharger will not power up/ Boost

[Gtsi-R]

hi,

driving a gze for 2,5 years now,

but got the problem lately that the SC wont power up/ come in. problem occurred occasionally first, but it is getting worse by the time..
I am even lucky when I got it working now

it is a electro-magnetic powered clutch, driven by engine vacuum?

but how does it exactly work?

I have spend 30 min of trying to find a bad vacuum hose, but with now success. finally the clutched got powered again, and I can see that the clutch itself is OK, and functioning like it should,

so I have to look in the "steering side" how does the electromagnetic clutch get his signal???

could someone help me out here?
cause I need the boost!!


and a second question:

what is against a direct and always powered SC? cause you can install a BOV? or am I wrong?

regards and thanks for your help

Roel