1987 300TD, with 87K miles - the wiper arm stops about 2/3 to the right when set on intermittent wipe.

The problem started about 30 minutes into use during a rainstorm - the wiper arm suddenly stopped in mid cycle. The wiper remains fully functional in low and high speed settings but stops mid cycle in intermittent. The arm also now parks in that same position when the wiper is turned off, regardless of speed setting selected.

Switched out the wiper relay with a new unit, without success.

Turn signal combo switch defective?