'76 930 with no boost
 

The wastegate has been removed/inspected, and appears to be functioning properly when 20# air is applied. I would think the next logical area to look at would be the bypass valve.

Is there anything within the bypass valve system which has been problematic? I am assuming not, since there is little contained on the subject within this forum. How does this circuit function?

I do not have the turbo shop manual, so have not been able to read up on how this system functions. How would I troubleshoot the pressure switch (P/N 930.606.101.00) in this circuit with a VOM?