2008 MCS with Auto Climate and factory heated seats. Passenger’s heated seat works as normal. Driver’s seat doesn’t work in any of the 3 settings even though the button lights up as normal. I’ve run the car for over 45 mins and no Change in seat heating. I’ve swapped the seat heating modules (under each seat) and still not working, but the passenger seat continued to work normally, which ruled out a bad module. Plugged the heating elements into the passenger side and they heat up. Fuses are good.
I’ve seen a few posts on the web for the same issue for the driver’s seat, but no resolution or root cause is posted. I’ve connected the multimeter and can see the current change at the module with each setting from the button and I have power coming into the module. What am I missing?

Any suggestions?