[Quinten]

Just wondering if someone has had this issue, and maybe knows where I can start looking before I need to bring it in for help.
My '06 e90 rear defogger is not working. It starting fall of last year, working intermittently. I could turn it off and on a couple of times then it would work. The last couple of months it doesn't work at all. The light on the switch comes on when pushed, and the fuse checked out OK.
Anyone have any clues as to where to look?
Thanks.
Q.

[csupernova]

last time i had the exact same problem. I changed to a new car battery and problem solved.

[Quinten]

Thanks for the info. Maybe it needs some sort of "reset"/power down sort of thing?

[john_e90bimmer]

You need a new battery, see my post here I had the same problem http://www.e90post.com/forums/showthread.php?t=482754

[GMWNashville]

yep-battery issue likely or IBS problem. Both will cause consumer cutoff issues and thus turn off the rear defroster. Check the battery and scan for any IBS

[Quinten]

John, thanks. I read your issues regarding similar symptons. Did your symptons go away once the battery was changed? (I am assuming they did)The other similarity is my heating blower will continuously change speeds from like low to med. to med high, then to low, then back up. It just doesn't stay steady unless on defrost mode. So this might also be a sympton of the battery?
One question, and I will search, but just in case, what is IBS?
Thanks guys.
Q.

[timmahh]

Originally Posted by Quinten

John, thanks. I read your issues regarding similar symptons. Did your symptons go away once the battery was changed? (I am assuming they did)The other similarity is my heating blower will continuously change speeds from like low to med. to med high, then to low, then back up. It just doesn't stay steady unless on defrost mode. So this might also be a sympton of the battery?
One question, and I will search, but just in case, what is IBS?
Thanks guys.
Q.

IBS = Intelligent Battery Sensor (I believe)

The blower speed may also be a result of a bad or failing battery, but that's also a symptom of a bad final stage resistor. It sounds like a battery is needed no matter what; start with that - then see if all of your issues are resolved.