Boost gauges are very useful tools for any turbocharged vehicle, especially when modifications or upgrades are made to the turbo system. The Mitsubishi Eclipse turbo vehicles lack a stock boost gauge, making it impossible to monitor turbo boost activity. If you've upgraded your Eclipse's turbo system, or even just increased the boost on the stock turbo with a manual boost controller, the likelihood for failure of vacuum seals and other stock parts goes up drastically. Installing a boost gauge in your modified Eclipse will let you monitor the turbo system's boost pressurization in realtime. This way, any turbo system malfunctions which effect boost pressure can be diagnosed immediately.
Disconnect the vehicle battery to ensure electrical safety during installation. Use a razor to cut the throttle vacuum line in two. This is the rubber line leading into the throttle body, at the rear of the engine bay. Connect the ends of the cut vacuum line onto the T-fitting supplied in your boost gauge kit.
Mount the gauge pod onto its intended location in the Eclipse interior, such as to the A-pillar, or atop the steering column. The pod will mount with supplied double-sided tape and/or Phillips-head screws, depending on model.
Connect the boost gauge ground wire and lighting wire to their designated terminals on the rear of the gauge. Place the boost gauge into the pod, running the gauge's wires and vacuum line through the rear of the pod.
Loosen one of the chassis screws, found near the door in the driver's side footwell area. Route the boost gauge ground wire to this screw. Twist the wire's exposed end around the chassis screw's neck. Retighten the screw, and wrap the connection with electrical tape.
Route the boost gauge lighting wire to the fuse box, mounted underneath the driver's side dash. Remove the fuse box cover. On top of the cover, you will see a fuse layout diagram. Use this to locate the fuse labeled "Gage." Remove the "Gage" fuse, and tightly wrap the boost gauge lighting wire's exposed end around the fuse terminal. Replace the fuse and fuse box cover.
Use a razor to make a small slit in the steering column boot, just above the foot pedals. Route the boost gauge vacuum line to this location, and work the vacuum line into the slit on the steering column boot. Continue feeding the vacuum line up the boot, into the engine bay until no slack is left on the interior side of the vacuum line.
Connect the end of the boost gauge vacuum line into the T-fitment installed into the throttle vacuum line in Step 1. Secure all of the excess vacuum lining aside with electrical tape. Reconnect the battery, and start your Eclipse to check for proper boost gauge operation.
