Dave's write up and test procedure is very good.
If you don't have a spare actuator you can use your pressure and
vacuum tanks instead. If you don't have a vacuum/pressure pump?
Autozone or someplace like that should have one. You can even sometimes
rent them or get a loaner pump. You can also make some jumpers and just
use a car battery for applying the volts.
If it is a secondary turbo issue? It is probably one or all of the following.
One or both turbo control solenoids.
Charge relief solenoid.
This is assuming you have checked all tanks hoses and check
You can get new solenoids from Ray at Malloy for about $50.00 a piece.
I think you can get most or all of the solenoids out without removing
the rats nest. You will have to remove the coils to get them out, not a
big deal if you removed the UIM. Use a long screw driver to gently with slight
forward and down pressure on the solenoid clip to remove from the rack.