Rear window demist issue

[pmansson]

It is rare for me to drive the cars when they have been left out at night, but today it was just early evening and yet a layer of dew. It had just gotten dark, and hence it was very easy to see, in the rear view mirror, that the bottom 3 electrical wires did not work.

What is the issue here please?
The rest of the wires started working very fast. Actually much faster than on another of my cars, where the actions is slow and weak.

Grateful for any hints...

 

[61porsche]

Rear defrost

Either there is a break in the electrical grid or a loose connection.

Here's a website that expains more and solutions: http://www.frostfighter.com/