Dave A

I haven't checked the voltage across a bulb yet - that's a good idea and I'll try it. I don't have a schematic, so I don't know if there's a voltage regulator in the circuit. That certainly could help explain why all the bulbs are burned out, if there's been a spike maybe it took out a bunch at once. Do you know where a good schematic is? I'll search for one as well. Thanks for the suggestions!

That's what I'm afraid of - that everything has just burned out over time. Still hoping that someone will have a magic solution of a fuse or wire to check, but that hope is fading fast. Wondering if something happened to this before I owned it that blew it all out at once. Just can't imagine that everything has gone bad. Thanks!

- Yes, the turn signal lights on the dash work. It's just the backlights on the dash, and all the buttons. And I don't believe they're LED? but I could be wrong. I know they're all soldered on to the dash and a pain to change. - I thought of the dimmer switch as well. Took it out, checked it, cleaned it, seems to be working fine. You can see the PRNDL light dim when you rotate the switch. Any other thoughts out there? Really hoping there's a fuse just for the backlights but that's probably just a fantasy.

Need help with my 2005 suburban with 225k miles. Bought it used needing some mechanical repairs. Those are done now and it runs perfectly. Except almost ALL the backlights for the dash, radio, heater control, rear heater control, steering wheel buttons, etc. don't light up. The PRNDL and odometer work, the check engine light and other warning lights work, the radio time/station display works, so it's just the lights behind the gauges and in the buttons that don't. To make it even weirder just one button is lit up - it's the button to push for 4x4 low range. Could all the others really be burned out? Or could it be a fuse? I've looked through the manual and can't find where there's a fuse for just the backlights. Just seems really weird that every light would burn out. Any help would be great. Thanks!