jjb3

Noticed when I was cleaning new C300 that there are gaps in the rear defroster lines that are intermittent. Can't test it since it's summer, but anyone else have gaps in their defroster lines?

Dstopsie

It’s normal. I had those on my 2020 C300 too.

bishop64

If all those lines are indeed defroster lines, then a break would, indeed, not allow current to run through to generate heat to do the job.

However, sometimes and often, some of those lines are actually antennae for various purpose (GPS, radio...etc).
And, obviously, these lines should not be connected to the defroster lines.

One way to be more sure is to take a pic of the rear window to show clearly the 'gaps' and post it up here.
Then, many other C300 owners can take a quick look at theirs to compare with yours.
I bet, the 'gaps' are exactly at the same locations, thus proving that the gaps are to separate the defroster lines and the various antennas.

Heloflyer68

Following up, has anyone noticed if the 1/3 top of the rear window cannot be defrosted? I turned it on twice to dry the morning due and the top part did not defrost.

jjb3

Dealer told me that above the 5th line or so is all antenna. So not sure if that explains the gaps and lack of defrost. I haven't had frost yet so don't know.