940 Dashboard Illumination Failure
 

Any help in restoring the lighting to the dash and switches would be appreciated. My 1997 940 has lost all illumination. I knew a couple of the bulbs had gone but everything has now failed although some bulbs are intact.
Having found a wiring diagram online for a 95 car this appears to match. Fuses 21 and 22 are OK so suspected the rheostat. This is wired as follows:-
Pin 1 White Supply from fuse 21
Pin 2 Green/Brown Output from Rheostat
Pin 4 Blue return supply for lamp
Pin 6 Black Ground

Voltmeter shows 12v across 1 to 6 and 4 to 6. Voltage across 1 to 2 is 8v with slider at max and 4v at min. Bridging 1 to 2 makes no odds from which I conclude the Rh is OK?

Am stumped as the where to go next. Any ideas please?

You probably should have measured 2 to 6 for the output voltage, but you likely would have seen nearly the same thing, just the other way around.

my 92 740, about half the dash lights are out, none of the switches light up, nor does the shifter, but the instrument panel and the AC controls do work fine. I need to sort this out.

Thanks Pierce my typing that's wrong! Input voltage was 12v across 1 to 6 and output measured 2 to 6 being 8v max 4v min. Good luck on getting yours sorted.