Thanks for the tip. I ground the blue wire, still no light. I will pull the inst. cluster and check the bulb.
I also posted this on the diesel forum and have been in disccusion with Jim and Brian.
Without rehashing all the discussions, I think the most pertinent is this:
If the alternator is disconnected there is no voltage loss on the battery
If the alternator is connected there is slow voltage loss (in 1hr. 12.04 volts down to 11.74 volts).
The brake wear light is also not lighting and in the wiring diagram I see they are on the same fuse, could they have been blown by a faulty regulator?
The low fuel level light also used to come on and now it is not. I don't see that it is on the related fuse. I am guessing one electrical problem can lead to many others.