Mechanical issues repaired, now for the electrical... [Archive] - Bimmerfest - BMW Forums

: Mechanical issues repaired, now for the electrical...

06-27-2012, 02:56 PM
So I just spent just over $3100 on a few leaks that I've had for some time(I'll post a pic of the paperwork later), and now I still have almost another $900 in electrical repairs. Just wondering if there was any other symptoms that may be causing my issues before I go throw money around.

My issue is that my computer seems to "go to sleep" as the dealer put it, and then resets/restarts every 3-5mins, effectively blowing out my driver side speaker as well as being insanely annoying when you are trying to listen to a song you like. The dealer had told me that this issue is caused by a low voltage battery that I currently have in my vehicle. Now I understand that my 745i has almost 4 fuses boxes, but could a low voltage battery really be affecting my iDrive/computer that much?

And note, that this problem is NOT intermittent. It happens every single time I start my car and drive it.

06-27-2012, 04:05 PM
In short, yes. A low voltage battery can drive you and your car nuts. The power module will regulate the power to your car, if it sees that the voltage is low it will start shutting stuff down.

My car did some of the same things, I would stick my key in and the radio would make this awl full low rumble noise, meaning the voltage to my amp was being cut off or low voltage supplied.

I also had other problems like the cd player would reload CDs every time I would get into the car, my eq settings would reset, and my max AC would not turn on full speed.

I did purchase a new battery and alternator to try and fix my problems. Independent shop said they registered the battery, I had the same problems until I purchased a cable and registered my battery myself.

I would say this is the #1 problem with the e65. People take shortcuts and the problems still are present.

You might put the battery on a slow charger for a day and see what happens, one night it will be back to normal as the charge will not last long at all.

06-27-2012, 04:38 PM
Appreciate the detailed response :D

Slow charger won't do anything I'm assuming, since it's a lower voltage battery and it isn't putting out enough in the first place, causing my issues. I guess I'll just give in and get the battery/computer reprogram together and hope for the best.

06-27-2012, 04:55 PM
Well, what kind of battery do you have? It might just need to be registered, and how old?

06-27-2012, 04:56 PM
Btw just trying to save maybe 900.00 bucks?

06-27-2012, 05:00 PM
Does the car start up like its on a low battery or right up? When the radio cuts out do lights dim or anything at the same time? Maybe idrive dims or flickers?

Sent from my SCH-I500 using Bimmer App

06-27-2012, 05:41 PM
As far as I can see, I have no other issues with the vehicle relating to the battery from start up, driving, and shutting off. I first hear the speakers sound like they are being shorted/blown out(differs each time), then my console screen flashes and goes back to first screen with the Call Assist and Lat/Lon, then to the first warning message. Tap the knob a few times and I'm back to whichever screen I was last on. Sometimes it's so fast that all I hear is the speakers go, but the screen just flickers and doesn't do the previous and stays on the same spot.

06-27-2012, 08:35 PM
Have you checked the voltage from the menu on the dash? Reason it might be alternator related.

Find a good shop that has experience with the electronics, my Indy is great at fixing mechanical issues, but both times my car went in for repairs pertaining to electrical issues he FAILED... My blinker didn't work and he suggested a new headlight, it was the LCM, my AC didn't work on high and he suggested a final stage resistor, I registered my battery and all was fixed.

06-28-2012, 12:35 AM
I have not checked the voltage, as I did not know you could do that from the dash lol.

And as far as indys go, I have been hard pressed to find one around here in Colorado Springs. I'd have better luck closer to Denver, but that's just over an hour away and just inconvenient.