[kevinbowe2000]

Hi all,

I recently bought a 2017 B9 A5 RHD. Rear window isn't defrosting, but the light on the switch is coming on. Thought it might be a bad battery but that's all fine. So checked the fuse, and there doesn't seem to be one in the slot for it. Am I misreading the fuse diagram, or should there be something in slot A7 in the boot? And if so, does anyone know what rating it should be.

Thanks in advance.

 

[TheFishBlub]

Hey Kevin,

Did you manage to solve the problem? I am in the exact same boat.

 

[kevinbowe2000]

Sadly not. Have tried a few different fuses bit nothing working. I have seen on other threads, that people tend to put the cabling back on wrong after a rear window replacement. Haven't checked yet if that is what is wrong.

 

[TheFishBlub]

I thought that's a B8/B8.5 issue. Seems like I am going to Audi for this one 😭

 

[kevinbowe2000]

I thought that's a B8/B8.5 issue. Seems like I am going to Audi for this one 😭

Ah, I hadn't appreciated that. Thankfully I hadn't started pulling things apart and broken clips If you do go to Audi, can you let me know the outcome please? I had thought that it may be a battery issue. As in that, there wasn't enough reserve so the ECU was killing the rear window. But I got the battery tested and it's all fine. Are your wing mirror heaters working?

 

[TheFishBlub]

Yeah, heated wing mirrors are working fine. I have just looked at my fuse box for the same, I am concluding that I may be missing the fuse altogether due to which it may not want to work.. which would be a weird one. Check image

Waiting for a call back from Audi to confirm how many amps the rear defroster takes.

Ah, I hadn't appreciated that. Thankfully I hadn't started pulling things apart and broken clips If you do go to Audi, can you let me know the outcome please? I had thought that it may be a battery issue. As in that, there wasn't enough reserve so the ECU was killing the rear window. But I got the battery tested and it's all fine. Are your wing mirror heaters working?

Dw, glad I was able to save you from pulling clips.

 

[kevinbowe2000]

I called a couple of audi garages, and all were useless. "It is in the manual" - no it isn't. "It is printed on the fuse box cover" - nope its not. Hopefully you can get more useful answers than me.

 

[TheFishBlub]

Let's see. Audi Reading has been good to me so far. They even did a job for me for free. Previous Audi garage (prior to my ownership) overfilled engine oil. This garage identified and removed the excess. Quite happy so far

 

[TheFishBlub]

Parts have let me know that it requires 40AMPS. Just need to confirm the position because they want it in a fuse carrier that doesn't exist in my car. 🤔

 

[TheFishBlub]

Just got confirmation Parts Department misread the diagram. Follow Owners Manual. 40AMPS.

 

[TheFishBlub]

UPDATE: Doesn't work. Will have to book it in with a specialist or Audi.

 

[kevinbowe2000]

UPDATE: Doesn't work. Will have to book it in with a specialist or Audi.

Annoying. Let me know how you get on.

 

[kevinbowe2000]

UPDATE: Doesn't work. Will have to book it in with a specialist or Audi.

Any chance you for any information from Audi on this issue. I'm still drawing blanks.

 

[TheFishBlub]

Any chance you for any information from Audi on this issue. I'm still drawing blanks.

I had the car checked by my local mechanic. He had run a full diagnostic check. The button clearly works and the car wasn't throwing any faults or errors. I need to take out the C-pillar trim and check the connection —apologies for no update.

 

[91_gd]

I had the car checked by my local mechanic. He had run a full diagnostic check. The button clearly works and the car wasn't throwing any faults or errors. I need to take out the C-pillar trim and check the connection —apologies for no update.

Hi, did you ever find the solution for this? I feel that my car is suffering from the same issue...

 

[TheFishBlub]

No, I haven't. I will have to take it to Audi or a VW/Audi specialist.

Hi, did you ever find the solution for this? I feel that my car is suffering from the same issue...