Amal should click when ignition turned on, if it is faulty it will not bleed off boost and so will be closed and send all boost straight to actuator which is why I said it's effectivly doing the same thing as what you have done now, but this won't be your problem as you are not making boost at all which will be something to do with turbo.
I guess the compressor to intercooler hose hasen't split?
Martin