hey william,
an easy way to test is to swap over the switch from the passenger seat (they don't need the bolster adjustment anyway
) to see if it's working.
they come apart easily and you will be able to see where the issue lies. there's a piece of molded rubber in there to keep the button 'in place' and actually make the switch work. i bought a spare one on ebay for about $15 (my passenger side one wasn't working 100%). if you need that part, let me know, i should have a spare.
peter
2004 330i ZHP
2005 330iT ZHP
2010 328iT M Sport
2012 128i M Sport