Hey guys, I bought a 97 A8 4.2 Q in June 07 and it had a cracked rear windshield (dont ask me how) so I got it replaced and never thought to check the rear window defroster. So come winter (utah) and it doesnt work. So I check the obvious first, fuse, and it is good. So I checked my Audi service manual and it talks about using a voltimeter to test it, etc. So to make it short, I havent tried that yet, but to be completly honest I am not sure I understood the manual. So does anyone have any ideas of what to check, is there ways to check the connections with out removal of the rear windshield, cuz that would suck. I am not sure it worked before I had it replaced, so I would like to see if I can fix it before I have to take it back to the glass shop.
Thanks in advance.

 

I have no experience with an Audi window...but other defrostersI have worked on I would assume to be of a similar nature.

-Check the connection to the rear window...there should be some kind of plug connection. Could be loose, dirty, broken wire, or not connected.

-Check for breaks in the actual defroster grid on the window (inside surface). If you find one you can get a repair kit...basically a paint on substance that conducts electricity. Sounds alot harder than it actually is.

My bet is it's not even connected.

 

To check the defroster with a meter you can touch one of the leads to the defroster on the inside of the glass and another to ground with the defroster on. You should get some voltage between 0-12 if your getting voltage back to the glass. One side will read near 12v and the other end near 0. If you have voltage there you have a ground issue. Otherwise your not even getting power to the glass. First thing i would do is remove thec pillars and check to make sure that the wires are connected to the glass.