So we just bought a used 2010 Mazda5 Sport here in Washington DC and I can't tell what the deal is with the lighting of the gauges. When driving at night with the headlights on the speedometer/tachometer/fuel gauge are somewhat hard to see. This is a problem especially at dusk when it's bright enough to seem like there's no light at all but not really dark enough to use your headlights.

When sitting still last night I noticed that with the headlights in the position between ON and OFF the dash was much brighter -- plenty bright! Seems like it should be this way all the time...but when you turn the headlights on the dash light dims considerably and is in my opinion nowhere near as bright as they should be!

I can't find any way to adjust this (my previous car was a stripped-down economy car and even IT had a way to adjust the lights) so in the meantime we're planning on keeping our headlights whenever we drive. I checked the manual and found nothing. Is this a design flaw or operator error?

Thanks all and I look forward to poking around and learning a lot more about my recent purchase

 

There should be two push button on the instrument panel, above the gauge cluster. The one on the right adjusts the tripometer from A>B>A again, or if held long enough, will reset the one you are viewing to zero.
On the upper left is a second button. This one sets the gauge light output in 5(?) steps.
With the headlights off and the ignition on or car running, push this button several times until maximum brightness is achieved. Turn on your headlights and see if the display has dimmed for nighttime viewing. Push this button again with the headlights still on and the gauge panel should light up as it does during the day.