superlazy

I bought a 98 ws6 off a friend last fall. One of the previous owners put in a gauge overlay that's acting up. When it's cold out it does not light up until the interior of the car has been warm for awhile, even then goes back off most of the time when you hit the breaks I believe it is tied into the parking circuit and my friend put a toggle switch under the dash so he didn't have to keep turning the lights on & off to reset it.
Well tonight I went to pick up my daughter and her friend from school, it's around 60deg out and it was fine all the way there, so I'm thinking it simply must be a temp thing.
Well sure enough I put the car in gear to head home and it goes out flip the switch off then on and they we fine on the drive home.
Although annoying for me I really don't like the idea of he wife getting distracted messing around with the switch.

So is this common? Should I tie it into a different circuit or maybe run a dedicated fused line? I really cant see them having very much draw.
While fixing the power seat today I found the trip odometer stick and spring they never reinstalled so I will be pulling the cluster sometime to remedy that so I guess I could just rip the overlay out but would rather just make it work properly.