What Is This Idiot Light For?

[Buzz]

Been having a Thomas spare bus for the past few weeks. Not very familiar with them before this always having had an International ... kind of like the Thomas buses, (except for the fact that many of them rain inside the windshield),  but I heard we're not getting them again. (Too expensive.)

Anyway, this idiot has no idea what the idiot light circled in the picture is for. Doesn't seem to change and I don't know what the little arrow is pointing to. ( I know it's not DEF.)

Anybody?

[OnTime]

My guess is something to do with cruise control option

[Buzz]

My guess is something to do with cruise control option

Hmm ... possibility. I notice it goes away when I put on the parking brake.

[Buzz]

My guess is something to do with cruise control option

YOU ARE CORRECT, SIR! Found a manual online for a different model Thomas but the icon is the same and it is the cruise control indicator. YOU WIN!!  (But I don't have a prize to give you ... LOL)