Problem:
the backlighting for the tach and speedometer and for their respective needles, climate control panel, etc are very dim. How dim? So dim that I thought the fuse was blown and didn't realize they were actually lit until i parked the car in my completely darkened garage.

What I've checked so far:
1. Fuse 21 - in the darkened garage when i pull fuse 21 I can actually see the instrument lights go out (and of course come back on when i replace the fuse).
2. ECU reset - the whole procedure of holding down odo reset button while turning key to on position and scrolling to menu "21" and doing the reset.
For those curious here's a link to the process:
http://new.minimania.com/ECU_Reset_P...50_52_53_MINIs
3. pulled kick panel to expose BCM (body control module). Connectors locked in place, no moisture visible in area (it's -15 here so moisture would actually look like ice). Pulled and reseated connectors just for good measure.
4. played repeatedly with the poorly designed (and labeled) dash brightness button. Holding down, pressing repeatedly, nothing happens, repeat... (and Einstein's definition of insanity is...)

FWIW, everything else electrical appears to work just fine. The gauges, speedo/tach needles, warning lights, turn signals, and so on all function.

 

Going to move you to the Stock Problems/Issues area.

Have you checked the dimming button?

 

Push the dimming button and hold, your lights should get brighter.

 

method for your vehicle may vary. This is taken from a gen2 countryman manual

Edit: sorry, I reread the OP's #4. You already tried this. Maybe that button is kaput.

 

If the lights go out when the fuse is pulled and the dimming button does not do anything then check the voltage going into and out of the button.

 

On #4, if you meant "repeating the same and expecting different result" as Einstein's definition of insanity, hate to tell you it is another greatest of urban myths. I would almost agree the dash brightness button is not the greatest, but do remember the tiny confined cabin the designers have to contend with. Once you set the brightness to your preference you should never need to mess with it - and because of it, I too was challenged to change the setting after 13 years since.

As to your problem with the dim illumination, check the voltage what the lights see. It could be too much remuddling by the previous owner. It could be loaded down by aftermarket "mods" like an audio head unit that was incorrectly install and loaded down this "dimmer" line. FWIW, as far as I know it is pulse width modulated.

 

On the pulse width, never took a gauge apart but they are LEDs and not good ole Edison type bulbs?

And on Einstein, allot of people do not know he was dyslexic and that his brain was stolen.

 

I have never looked into the cluster bulbs. I am under the impression they are Edison type.

 

They are LED. Look at the threads where people change the color of instrument lighting.

 

Good to know, and does make sense since most of the power control falls into the tiny SMT ICs inside the little BCM It is one area that I have no interesting in messing with even if they are Edison.

 

Here's the wiring diagram for the illumination: https://www.newtis.info/tisv2/a/en/r...ghting/tJXJHmS

Nighttime illumination for everything (instruments, center console, control buttons) is on one circuit which is a gray/red striped wire running through the car (marked GR/RT in the diagram, German abbreviations for the colors). It is driven by a circuit inside the speedometer ("Instrument cluster control unit").

Does your dimmer button have any effect at all? If not, the problem could be the physical button. Note that the dimmer button only talks to the control unit and isn't part of the lighting circuit itself.

 

Thanks for all the replies.
This may seem like an inane question, how does one safely remove the illumination button switch. Mine is the big plastic button type located to the top left of the speedo.
Further i guess if it's the instr. cluster control unit, how do you safely remove the speedo too and check the control unit.

 

The switch is part of the speedometer.
http://www.realoem.com/bmw/enUS/show...diagId=62_0392
https://www.ecstuning.com/b-genuine-...r/62109126992/
The instrument cluster control unit is the circuit board inside the speedometer that controls the gauges (and illumination).

I've provided some information that helps to understand how it works, but I'm afraid that not much of it might be of practical use. These parts were not designed to be serviceable (the entire part is replaced when something goes wrong).

If you are still interested in getting to the speedometer, here are instructions:
https://www.newtis.info/tisv2/a/en/r...arrier/2jGBksc
Follow the chain of preliminary tasks to first remove the dash trim panels.

 

Problem solved!
Thanks to RTW.
The electrical diagram allowed me to go through all the illuminated items on that circuit.
It turns out the tire pressure reset button was defective and the illumination wire must have been shorting slightly drawing all the current.
Of course trying to find the problem I broke the connector going into the pressure reset switch - how flimsy is that connector! (in hindsight, maybe the connector was already broken and that's what was shorting?)
So for now i have a nice bright dash, but am unable to reset the "TPMS" system.

 

Glad that we could be of some help.

This adds to the over 85,000 threads here on the Gen1 model. Just so much information here.

 

Check the button and the wires to make sure its connected to the center console TPMS switch.

https://www.northamericanmotoring.co...on-wiring.html

 

It's not connected now - when I removed the switch from the console the white connector broke where it meets the edge of the black plastic of the switch. So now the wires are just hanging there with some electrical tape around them.
Trying to source the connector from a wrecker.... doesn't seem to be available as a stand alone part.