convertible rear defroster and battery issues

oneprettybeast · 11-01-2014, 01:32 PM

i have a 08 135 6mt, I had the battery replaced by the dealership I purchased from due to a code for the battery being said, anyway I didn't know about the pairing and registering with the car, but after some time if I drive the car turn it off and leave the accessories on the battery indicator pops up on me, so I figure I need to get a oem battery and pair it, I have the bav tech software so I could do it myself n save a 100 or so.. but with that al being said on my rear defrost only one element come on to clear fog or moisture. and my top seems to be a tad slow... I checked the elements with a test light to determine if there is a break someplace in the elements causing failure.. but they all have power going to them being a dead end short I cant seem to figure out why... does this car have a safety mode that stops full power from going to certain modules. to use the power in more important places? heat/ac work starts right up but the battery light comes up now and again just no code... I ihave a p3 installed so when its running its staying charged at 14.2 give or take a point.. so its not the generator or alternato.......anyone know of a reason this could be?? I would be EXTREMLY GREATFUL FOR ANY HELP... and yes ive looked into it and even spoke to bmw but they way me to have them plug it in which is 130 soo ill try the real experts the enthusiasts

128Convertibleguy · 11-03-2014, 09:56 AM

The rear window defrost elements are known to fail. It's not always easy to see the breaks. The window cannot be replaced, only the whole top.

There are kits to repair them, and if you're not inclined, an independent shop could use them. Buzz on the Internet about those in generally favorable.

If you just had the battery replaced, and it started causing the light, take the car back.

11-01-2014, 01:32 PM	#1
oneprettybeast Enlisted Member 0 Rep 41 Posts Drives: e88 6mt 135i vert, injen dci Join Date: Aug 2014 Location: florida iTrader: (0) Garage List 2008 bmw 135i {N54} [0.00]	convertible rear defroster and battery issues i have a 08 135 6mt, I had the battery replaced by the dealership I purchased from due to a code for the battery being said, anyway I didn't know about the pairing and registering with the car, but after some time if I drive the car turn it off and leave the accessories on the battery indicator pops up on me, so I figure I need to get a oem battery and pair it, I have the bav tech software so I could do it myself n save a 100 or so.. but with that al being said on my rear defrost only one element come on to clear fog or moisture. and my top seems to be a tad slow... I checked the elements with a test light to determine if there is a break someplace in the elements causing failure.. but they all have power going to them being a dead end short I cant seem to figure out why... does this car have a safety mode that stops full power from going to certain modules. to use the power in more important places? heat/ac work starts right up but the battery light comes up now and again just no code... I ihave a p3 installed so when its running its staying charged at 14.2 give or take a point.. so its not the generator or alternato.......anyone know of a reason this could be?? I would be EXTREMLY GREATFUL FOR ANY HELP... and yes ive looked into it and even spoke to bmw but they way me to have them plug it in which is 130 soo ill try the real experts the enthusiasts
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11-03-2014, 09:56 AM	#2
128Convertibleguy Captain 60 Rep 704 Posts Drives: 2010 128 Covertible Join Date: Jan 2014 Location: Mountains iTrader: (0)	The rear window defrost elements are known to fail. It's not always easy to see the breaks. The window cannot be replaced, only the whole top. There are kits to repair them, and if you're not inclined, an independent shop could use them. Buzz on the Internet about those in generally favorable. If you just had the battery replaced, and it started causing the light, take the car back.
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