It may be in the owners manual, but I thought I would ask here first so I would not have to search, but does anyone know if the "o2" warning lamp is supposed to illuminate when the ignition is turned on?

I am wondering, because I have never seen mine illuminate, but ALL other lights work perfectly. I know that on most cars, that most lights will have a "check" moment, where warning lights illuminate, but I know there are some that do not. Oh, BTW - its a 85' W126 380SE.

Thanks!