Senecat

Any ideas/easy answers before I start doing my own research?

BenzV12

A pleasure to see you here Senecat but I'm so sorry as I would not help you out here . I have not seen anything like that before either

Bruce Hubbard

The conducting strips that are on the glass
are probably broken, open circuit for the strips that feed the lower part
so it is not getting any power

JettaRed

iTrader: (1)

Look very closely at the connecting elements that are not working. You will find they are corroded. At least your top half works. My 2015 SL400 is completely non-functional.

ygmn

what they sadi broken wire.
If you can feel the line on inside they do have repair kits where you kind a paint on a nail polish like special paint that is conductive, sticks to glass and the wires.

Or ask Safelight I think they can repair it.

Other choices are live with it or replace entire glass.

S-Prihadi

The window tinting guy from 3M Cyrstaline team told me, sometime when they are tasked to replace old tinting film to 3M, sometime when they peel off the old tint, those fine heater wires can get damaged.

Bruce Hubbard

It's a bit strange that it is the complete bottom section
If it was individual heating elements one would expect random failure, some work, some don't
Anyway, only one way to find out, you need to remove covers and have a close inspection

If all of it has failed it is usually the connector shown and you solder that back on to the conducting strip

Quint22

Mine is a litte different, about 1/3 of a portion of lower doesnt work right. There are some weird cross connects on the little heating elements. Leave it to wonderful intelligent german engineering to provide with multiple partial failures. Have not delved into it much as most of mine still works.

Senecat

Wow, thanks guys! Lots of good info. I will first check the connector/s, and inspect the elements. I'll post back with results. The connector makes most sense, as it is an even loss of one entire half of the elements. My rear sun shade is also not functional, and it looks as if someone might have been back there to attempt to repair it. So maybe a connector came loose in that process.