exhaust brake issue

Your sig shows an 06 model. You comments say 2002?

A 2006 probably is just as described and may use a variable ratio turbo for the braking.

A 2002 may have a mechanical one and need lubing.

If your exhaust brake was indeed "energized" where it was always closed, you probably wouldn't be able to move the coach at road speeds. If the switch stays lit, that is the way it is supposed to work.

If by energized, you mean the switch is lighted and the engine break is ready to work whenever you lift your foot off the accelerator, then YES, that's how its suppose to work.

My '07 Holiday Rambler Diesel with a 400HP Cummins worked that way. I drove with the engine break turned on all the time.

How about the brake switch?