The Stig

Hi Guys,

The rear windshield defroster on my sedan has stopped functioning after taking my car out of storage. The defrost switch lights up whenever I press it and the fuse appears to be good.

I have also checked the voltage on the defroster lines with a multimeter but there was 0 volts. My rear windshield isn’t tinted so, the defrost lines seem to have no chips or breaks.

I suspect that the problem might be a relay and/or the defroster element. I can’t seem to find the relay number & location or the location of element for the defroster in the Bentley manual.

Any advice would be appreciated!

The Stig

Update:

After calling an Audi Parts guy to figure out which relay controls the rear defroster, I was told that it is Relay #7 under driver's side dash panel. I purchased a new 40 amp relay from Napa and installed it, but the defroster still shows no voltage!

Then, I decided removed the driver's side D-Pillar interior trim to get to the Defroster contacts and element. I found 3 small boxes which seem to be related to the Antenna on the rear window. Is the element on the passenger side of the car?


Any help would be appreciated!

The Stig

I've been searching for previous posts to find a solution to this problem but it seems difficult to pinpoint. I'm at my wits end trying to figure out the cause of it....might be forced to take it to a local shop.

jsfunke

I have the same problem has anyone replied??

The Stig

UPDATE (Problem Solved):

I wanted to post an update on the issue and provide a solution to fixing the rear defroster.

I’m sorry for the delay in posting this update but I was swamped with work and traveling. I had a taken the car before Christmas to a local euro/import repair shop, which has done some work for me in the past.

An electrician at the shop checked the wiring for the system. I had already removed the D-Pillar covers, rear deck, and rear seat to expose most of defroster wiring and connections before going to the shop.

He started to remove the rear defrost switch from the dash to check the wiring and test it, but noticed a partially frayed wire leading from the switch (buried in the dash). The wire leading to the switch was replaced and the defroster worked again!!

However, I had neglected to inspect the switch or wiring leading to it (personally before taking the car to the shop). The switch still lighted and clicked when pressed so, I assumed that it was fully powered. I wasn’t suspecting it as the source of the problem.

Hopefully, this solution will help someone else to find an easy fix for the problem without having to replace the switch!