Hello,
I removed the instrument cluster out of the dashboard to change a single non-working bulb.
When I removed the Panel into the Dashboard again all other illumination bulbs / FM-Radio Frequency and digital clock
went off in the same moment ... ( so did the under-dashboard illumination of 2WD-4WD and the ashtray illumination).
All signal lights in the instrument panel like the green turn signal lights and blue full beam light signal for example still work.
When I switch off head light, Radio frequency and digital clock are working again.
I checked all fuses. All OK.
I checked voltage in the bulb holder (with no bulb in it) --> 15 V -- OK
I also changed the dimmer-headlight-switch against a brandnew OEM dimmer switch yesterday. Unfortunately the problem is still there.
I looked, if I have dimmer in a low/off position, but this is not the case.
I thought of a burnt fuse or a broken cable, but FM-Radio Frequency and digital clock still work excellent when I switch off headlight.
One more observation:
when I switch on the headlights, the white instrument-panel-illumination-bulbs glow for a second or two (not very shiny/strong in my view) and then they all go out immediatly .
When I wait for 20 seconds or longer I can repeat this experiment and let the bulbs glow for a second.
When I wait less then 15-20 seconds for the next try, the bulbs don't glow at all.
I still assume it must have something to do with the headlights wiring/relays/switches...
I looks, that I loose voltage in the bulb holders, FM Radio and clock when I switch on parklight/headlight
Any idea what to check next?