Alan,

If all was OK before the flush, then it might be the concentration or the
type of coolant used that is the problem.

The led can flash if it detects incorrect electrical current flow due to
incorrect mixture (have read this from a previous post).

I just flushed mine, using blue German Pentosion coolant.  I did the standard
Vanagon procedure.  It had no problems afterward.

I also added Redline Water Wetter.

I took a 160 mile trip with no problems.

I think it might be the "type" or "mixture" of the orange coolant that is
giving you problems.

Did you premix the coolant before adding?

Robert