1995 Ford Probe Multi-Stage Boost Control Vacuum & Wiring Diagram - Profec B

This is a hand-drawn (computer-sketched) vacuum routing and wiring diagram showing a custom multi-stage turbo boost control setup, uploaded to a 1995 Ford Probe gallery. A legend indicates blue lines are electrical wires and red lines are vacuum lines. Components shown include a Profec B boost solenoid assembly (with IN and OUT ports), a Precision hp5857 turbocharger, a normally-open vacuum solenoid, a normally-closed purge/EVAP solenoid, a Turbonetics ('Turboenitics') manual boost controller rated 0-25 psi, and the wastegate top/bottom ports. Electrical control is provided by two Bosch relays fed 12V, a hi-boost push button (also fed +12V), and a normally-open clutch pedal switch. The red vacuum lines route boost pressure from the turbo compressor through the Profec B solenoids, the vacuum solenoid, the purge solenoid, and the manual boost controller to the wastegate ports, allowing switching between boost levels. The blue wiring shows the relays energizing the solenoids via the push button and clutch pedal switch. A reader can learn how this owner plumbed and wired a switchable high/low boost system combining an electronic boost controller solenoid with a manual boost controller.