Where is the wastegate solenoid

- L Power Stroke Diesel - Disconnecting wastegate solenoid? - Hello. I've been diagnosing a low boost issue for quite a while. Save on Turbocharger Wastegate Solenoid at Advance Auto Parts. Buy online, pick up in-store in 30 minutes. How to troubleshoot the wastegate solenoid on a L GM diesel by checking the engine vacuum supplied to solenoid and the wastegate actuator.