Thanks to the assistance of the fine people on the list, all the wipers on my
'88 Vanagon Westfalia now work!

To recap here is what I had to do:

Rear wiper - did not work: Motor had self-destructed. Had to replace the
motor.

Front wiper - intermittent speed functioned as 'low speed': I disassembled
the front wiper relay, painted with a "19" on the top and removed the circuit
board from the container. Since I was going to have to replacing this relay
anyway, I thought I'd take a chance and try replacing components on it to see
if that would fix the problem.

In looking at the board, the capsitors seemed to be a good guess for what
might have failed. I went to the local radio shack and for about $3 I got the
two capasitors, one 220uf and one 4.7uf and replaced the original ones on the
circuit board.  Voila' ! I now have intermittnet wipers !!

It sure made me happier paying $3 rather than $50 at the dealer for the new
relay.

One tip for anyone esle considering this. Make sure that you note the
position of the negitive lead on the original capasitor so that the new ones
are installed the same way.