scoob-stu

Hi guys,
whilst out for a spin today, thought i'd give it a quick blast, only to find out i had no / very little boost. it was peaking at 7 psi, crap Any ideas??
i've tried plugging the test leads in under the dash, and the boost solenoid clicks like mad, although i cant hear it under normal running conditions. Should i be able to hear it whilst engine idling???
Dont think its the turbo, as i can hear it spooling.
checked all pipe work to dump valve, solenoid etc.
plz help