boost solenoid not clicking
 

hi been having a problem with my solenoid for ages works ok but when i go on a run and the car gets hot boost drops off to 0.5 bar and the solenoid has stopped working tried cleaning no joy no fault codes either reset the ecu ok till next run is there any other sensors that could be causing my problems car is a 95 wrx if i connect the green conectors it does click though

Check for a boost leak, don't know why it would happen when it gets hot but would cause the 0.5 bar and the soleniod not to click.