mirror does not heat, heated mirror problem, how to fix heated mirror, mirror glass replacing Renault Grand Scenic, Megane

What a month, few things just fell on my back, and just yesterday my alternator died too. It will be on the blog soon, just waiting for a new one to come.
Anyway today, again, simple tutorial on how to fix, check and replace heated mirror.
Let get started:

First of all we have make us sure if there is current getting to the mirror.
Put the card in to the terminal and just click the start button. This will let the power to radio, cigarette lighter, electric windows and of course to heated mirros.

In order to remove mirror, twist the glass as much as you can towards the car, then put your finger in the LHS upper corner and pull the glass out. You will need to use some force

Now let check the voltage

0.00 Volts....

You have to clean the electrical connectors, which are a bit rusty

Check the voltage again. 0.00 Volts again. Check the fuses or actually...Renault is very tricky... You have either start the engine or fully switch the ignition on (open driver's door and click locking button on the card, then put the card into ignition and push and hold the start button until you will see on dashboard controls on and you will hear nose from power steering. Now go and check the voltage.
YES TRICKY ONE.

We have a voltage.
BTW Do you know why did it show minus ?

Put the pieces together and check if the mirror is heating.

In my case mirror stayed cold. It was burned so I had to order new glass with mounting.

Thanks!