E34 have different versions, depending what system is installed. Here some links how to do
BMW E34 Website
kcbmwclub.com • View topic - e34 HVAC Instrument Panel Lighting
Replacing the E34 blower fan and temperature light bulb
IHKA BMW E32 Climate Control Illumination
IHKA LED BMW E32 Climate control LEDs
There are a couple of versions of the control panel. Verify which one is yours.
Awesome, thanks for randomly posting this, I just realised there's no cool orangey light with headlights/parkers on that panel in my e34 and have to yank the panel and check it all. Also the dial on the left (passenger side temp control) freewheels without the subtle click I can feel on the right one as you turn it to lowest or highest position. So some work to do there.