Update: Using LEDs for Instrument Cluster Warning Lights

Traditionally, automotive instrument clusters have been illuminated using incandescent bulbs. Failures of these bulbs are a source of warranty and repair costs. LED lamps can reduce these costs. In addition, LED lamps have a number of other benefits for instrument cluster designs.

This paper describes the design of a hybrid instrument cluster using LED lamps for telltale warning lights and bulbs for gauge lighting. This approach provides a very cost effective design since most telltale warning lights can be illuminated with a single LED. This approach eliminates three quarters of the bulbs in a typical design.

Previous SAE papers, 870211 and 900474, have also discussed the use of LED lamps for telltale lighting. These papers used very specialized lamps. This paper discusses several industry standard LED lamp packages in both through-hole and SMT package configurations. Lighting measurements have been done at instrument cluster depths of 10 to 41 mm, to cover most applications.