Gauges back lights

I have just collected my 1989 90 from a full body rebuild and am now in the process of installing some goodies - mud dash with loads of lovely gauges, rocker switches, etc. I am a complete numpty when it comes to electrics. The mud dash worked brilliantly when tested directly to a battery outside the vehicle but when I tried to connect it to existing circuits on the vehicle I got a big, fat zilch.

The backlights on the factory-fitted gauges (gauges are being replaced too) are not lighting up when the sidelights (or headlights) are switched on (bascically the red/white wire doesn't seem to be getting any current. I have given up and will take the car to an auto electrician tomorrow. My question is this... for a reason that I just cannot understand, the switch that illuminates the courtesy light in the cabin (i never had a courtesy light so i left the switch well alone) turns the gauge back lights off when the courtesy light is on. In order to avoid confusing the electrician, I need to know which position the switch needs to be to turn the back lights on so he can get a current when prodding about with a multimeter.

Well you’ve confused an aircraft electrician!

So going back to basics here and ignoring the courtesy light & new pod - do your Speedo backlights etc come on with your lights?

I should have added about the switch, is it the 3 way one you’re referring to? I’d pull the switch and see what colours are there and go from there with the help of a wiring diagram.

right now they're not coming on. there must be a severed wire or lose contact of some sort which is why i want to know which position the three-way switch should be in in order to illuminate the dash.

Don't think the 3 way switch (the slider on the roof lens/unit?) is intended to have any effect on or off on the dash lights? Don't recall mine ever doing so.....but got me wondering now......! Shirley an autoelectrician will suss it in 5 seconds flat anyway - I'd let him/her exercise their skills! Good luck anyway - I'll keep an eye out for an update and anyone who knows what they are talking about. Cheers, A

Do you mean this switch (attached).

Top of the switch with the picture of the clocks on to be pressed in.

Switch in middle position switches dash & interior off .
Switch down is for interior light.

Check fuses with a meter

Sorted! I removed the switch to see where the where the wires went and where did they go? Bloody nowhere! The plug was disconnected. Pushed it back and voila! Thanks chaps