Instrument cluster 2011 Jetta Sportwagon

Over the past few days I have noticed that the speedometer and Tachometer lights have been alternately dimming and brightening. This happens during daylight driving. This evening they were completely dark and started to brighten but ever so little then went completely dark and stayed until I got home. Earlier this year I had the odometer problem and that was repaired by the dealer. I have 19,400 miles on the car. The lights work fine with the headlights just have the problem during the daytime, has anyone experienced this? This only affects the speedometer and tachometer. Thanks, Bob

The instrument lighting will be bright when there is bright daylight. When there is dark overcast, deep shade or when inside a garage the lights dim to remind you to turn on your headlights. They do this because the daytime running lights don't operate the side marker or tail lights- you have to switch on the headlights for those to come on. It's in the manual.

At least that's the way it works with my 2010 JSW.

Yup - perfectly normal. There's an ambient light sensor on the dash board that adjusts the back lighting based on ambient light.