Instrumentation Illumination Question

[guruerror]

Does anyone know the specs for the little light bulbs used in the various instumentation controls? Specifically, what voltage is applied to illuminate these bulbs? 3.2 volts? 5 volts? 12 volts?

Why am I asking? What am I trying to achieve?

I've been struggling lately to keep all of the lights on the various instrument controls lit...buttons for the AC, icons around the rear wiper, headlight control, etc. These little bulbs seem to burn out after about 3-4 years of use.

Recently I purchased a replacement AC control unit from a fellow member to repair my defective one, unfortunately the replacementt control has several buttons that do not light up when the headlights are on. I disassembled the unit and found the bulbs to be burnt out. To my surprise, the bulbs were incadescent and not LED. My goal is to un-solder these bulbs and replace them witth LED 'bulbs.'

A recent trip to Radio Shack led me to discover that LED lights are available in 3.2 volt and 5 volt versions. Hence this thread...does anyone know what voltage is applied to the OEM incadescent bulbs? I realize that I can probably figure this out on my own by connecting a voltmeter to the bulb's leads while the headlights are on...but I thought I'd throw the question out there before I go down that route.

My ultimate goal will be to replace all of the incadescent bulbs in the various controls with LEDs. It's a full-time job trying to keep all of the instumentation lit and I hope that LEDs will keep this from becoming a recurring problem.

Thanks in advance.