Project Explorer: Blue Instrument Lights

The replacement headunit for the Explorer is a Sony CDX8805 unit. This has a fluorescent blue full motion display with blue LED lighting. It looks really good and modern and I decided to make the dash and other interior lights follow the same scheme. Unfortunately, this was easier said than done. Most of the interior lighting (dashboard switches, door locks and window switches all had enclosed bulbs or really small bulbs that are really difficult to replace. Furthermore, the green OEM lighting was not dependent on the bulb. The light housings had a form of colored coating that rendered the color. The only solution was to remove or scratch off this film.



Instead of dismantling the gauges, I wanted to make sure that my experiment would work. I obtained the gauge faces from a dismantling yard. The Ford OEM gauges are basically composed of the mechanical and electrical assembly topped with a thin plastic overlay. These overlays have the calibrated markings for either metric (kilometers per hour) or US Miles per hour. Under normal lighting conditions with 168 or 194 bulbs, the resulting color is the OEM green.



Replacing the bulbs with blue LED's or blue-coated incandescent bulbs did not result in a change of color. In most cases, it just grew dimmer but still showed a very faint shade of green. In this picture the blue lighting was simulated using a bright blue neon tube. The output from the neon tube was significantly more than a standard LED, therefore even the brightest 168 compatible replacement LED will give an even dimmer result.



The overlay has a thin white film coating on the underside. Using a craft knife with a rounded blade, the coating was carefully scraped off to reveal the underlying clear layer. The black outline on the picture shows the area that needs to be removed.



Here is a side by side comparison of the odometer area where the coating has been scraped off. In comparison, the speedometer area on the right side has not been modified yet. Bright light on the underside is used to simulate OEM lighting. With the green coating removed, any light will now show through the gauge overlay.



The final results show the blue light shining through the overlay as expected. The only remaining step would be to replace the existing overlays with these modified ones.