tomm,just went through the same drill with my E300 D,and found the cure,you will have to replace the signal stalk on the steering colum,
That switch does seversal things and the Hi/Lo beams is the main on.
You can check the dipper and see if you have high beams,that will prove if it is the switch,you should have hi beams when you hit the dip switch.
Have fun, Tom Brown \
Va section