The Electro-Luminescent Instrument modification for '65-'73 Mustangs from Mustangs Plus is a groovy restomod trick because it looks great and helps you see the instruments better at night. Pioneered and manufactured by Scott Drake Enterprises, the Electro-Luminescent instrument face is a semiconductor that offers a soft green or blue glow when the parking lights or headlamps are turned on. You can also wire it to light up whenever the ignition is turned on.
We're going to install the Electro-Luminescent kit in a '67 Mustang instrument panel. Some minor modifications are required, which are easy to perform on your home workbench. You can take two approaches with the installation: ditch the factory instrument lamps or keep them. If you keep them, you can see the odometer better and they'll also provide some fill-in light. Keeping them also means you'll have to use a different approach to wiring in the Electro-Luminescent faces.
Important PointsScott Drake Enterprises suggests getting your Electro-Luminescent power from a circuit independent of the instrument lights. We tried getting ours from the instrument light circuit (blue wire with red stripe), which would theoretically make the faces light up when you turn on the parking and headlights. We wanted to keep the Mustang's instrument lights working in conjunction with the Electro-Luminescent faces for fill-in light. Because the instrument lamps ground through the metal cluster, they tend to interfere with the faces. When we disconnected the lamps, the faces worked. When we installed and grounded the lamps, the faces did not work. If you desire both, here's what you must do for proper operation. There must be an insulator between the plastic chromed bezel and the steel instrument cluster. Electrical tape works well, as does a rubber strip. This keeps the chrome from carrying stray electricity, which adversely affects Electro-Luminescent operation.
We also learned it isn't advisable to get your Electro-Luminescent power from the instrument lighting circuit (blue with red stripe). It doesn't like resisted current, which comes from the headlight switch. Instead, get the power from the parking-light circuit. This provides unresisted current for proper operation. With the Electro-Luminescent faces and factory instrument lights operating on separate circuits, you're free to control both lighting efforts independently.