14: T680 Kenworth Driver Academy - Instrument Cluster Indicators 

Doyle Lee that is showing your jake brake is on.

Go to settings on your dash and turn that option off. Easy

Christopher Hernandez check and see if your fan switch is on its to the left of your cruise control switches

It may be on frequently if weather hot and your AC turned on.

Charles Spencer I'm not sure but I'm gonna guess it is your rpm gauge for shifting, I just bought a t680 and I have lots of questions, but of course I come up with these questions when I'm on the road,😎

No, I drive a NEW one with allison auto, they are present as well. during test drive too.

Optimum shift points for optimum fuel economy

My employer states that, that is the optimal cruising range for the best MPG

I'm trying to figure out the same thing. Only mine is green. The switch is in the sleeper. I'm assuming it's for a fridge, but I don't have a fridge. The light on my dash illuminates green, not blue.....2015 KW T680

If it's in the top left, under the outside temperature reading. I'm pretty sure it's just warning you that the roads might be icy.