Technical Rear defroster not working

[grun500]

My 2008 500 lounge has a not working rear defroster. Also the heated mirrors do not get warm. I checked the fuse f20 30Amp, but it wasn’t blown. So I think there will is something wrong with the relay.
When I push the button for defroster, the indicator light will not go on.
Where is the relay for the defroster situated and can it be replaced or could something else cause this issue?

 

[A3jeroen]

Inside the BCM. Hatchwiring 100% Ok?

gr J

 

[grun500]

I will check wiring, but mostly if hatch wiring is damaged, you will have short circuit. As I have written, fuse isn’t blown.

Is the relay of the defroster part of the bcm? Or can I change the relay?

 

[steveras57]

I will check wiring, but mostly if hatch wiring is damaged, you will have short circuit. As I have written, fuse isn’t blown.

Is the relay of the defroster part of the bcm? Or can I change the relay?

In my haynes manual it shows a "heated rear window & mirror relay" in the engine compartment fuse box marked as R 19

 

[John202020]

I think also separate fuse for mirrors 5a, 30a rear screen

 

[Ralf S.]

If the BCM was moody, the heater switch "on" light would still illuminate. Relay is my bet, if the mirrors are on separate fuses and yet both stopped working at the same time as the rear window. Obviously the switch itself is also a part in common, if the relay looks good.


Ralf S.

 

[grun500]

Well the weather is not cooperating
As soon as it gets better I will start investigating.
Thanks for the hints
Keep you updated.

 

[steveras57]

Well the weather is not cooperating
As soon as it gets better I will start investigating.
Thanks for the hints
Keep you updated.

Only takes 2 minutes with the hood up and a coat on to swap the relay around!

 

[grun500]

I’m made of sugar

 

[steveras57]

I’m made of sugar

best not go outside then in case a dog try's to lick you!

 

[grun500]

Just had some time to check the relay. Pulled it out of the car and supplied 12V dc to the pins and the relay was clicking.
Then I checked if the contacts also closed. That was also ok. Next step will be the wiring in the sleeve.