So my new to me 90 350SDL has only the left side (both front and back working), but no right on the Becker original. Balance adjust does not help.

Was this a weak link (sorry if this was discussed a zillion times) in the W126's or could just a wire/socket be loose, corroded or fallen off?

Should I be looking for a rebuilt unit vs. and older working unit (that will break due to it being "weak")vs. a "new fangled" replacement?

Thanks,

PK