[JunkyardDogg]

Strangest thing happened. Last time I drove was yesterday. Today I unlock the trunk with my key fob to take out a ball for my dog. I go and play fetch. I come back to the car and the key fob doesn't open the trunk. I open the car door, and no electrical is working. Put the key fob in the ignition and nothing. Any idea what it could be? Battery was replaced less than 2 yrs ago.

[mainbearing]

Check the battery voltage first. Then check the alternator, particularly the voltage regulator.

[JunkyardDogg]

I thought a bad voltage regulator would gradually give you symptoms instead of it being completely dead. Do I need a voltage reader to check it?

[bizzleb109]

I've had something similar happen to me, was the power connection which started coming loose from the fuse box connection behind the glove compartment. There was a recall on this as well. To check open the glove box and on the right side of the fuse box search for the power cable wiggle it around see of u get electrics if so then thats the cause. Hope it helps.

[e91Owner]

Originally Posted by JunkyardDogg

I thought a bad voltage regulator would gradually give you symptoms instead of it being completely dead. Do I need a voltage reader to check it?

You can check it on your display or use a multimeter. If using the display, see below:

[JunkyardDogg]

Originally Posted by bizzleb109

I've had something similar happen to me, was the power connection which started coming loose from the fuse box connection behind the glove compartment. There was a recall on this as well. To check open the glove box and on the right side of the fuse box search for the power cable wiggle it around see of u get electrics if so then thats the cause. Hope it helps.

Ok i'll try that. Did you have to replace your cable? cost?

Originally Posted by e91Owner

You can check it on your display or use a multimeter. If using the display, see below:

My display is dead so I bought a multimeter. Ill check the battery tomorrow.

[e91Owner]

I didn't read your first post. You won't be able to check the alternator if the car's not running. If you are getting around 12V from the battery, you should be getting at least the accessories to come on, otherwise it's a different problem.

If you aren't getting a voltage reading from the battery, charge the battery first or jump it and then you would be able to check the alternator output. Before charging it or jumping it, though, check the BST or the connection in general.

[JunkyardDogg]

How do I open the trunk? I crawled into the back seat and didn't see where I can open it. I don't see any keyholes above the license plate either.

[e91Owner]

Originally Posted by JunkyardDogg

How do I open the trunk? I crawled into the back seat and didn't see where I can open it. I don't see any keyholes above the license plate either.

You'll have to jump it and then push the trunk release

[JunkyardDogg]

Originally Posted by e91Owner

You'll have to jump it and then push the trunk release

I got a jump and they said the battery was showing 5v. So I drove it around for 30 mins to recharge it and got home, popped the trunk, turned it off and immediately tried starting again and it failed. So does this mean my battery is dead and what could have caused it? Only thing I can think of is I didn't fully close my door. Can that kill your battery?

[ctuna]

You need to get a voltmeter.
And measure both the battery voltage and alternator voltage.
If your battery was 5 volt it's probably shot.
You could try putting a long charge on it like at least 5 hours
and see how long it holds the final voltage.
Average life on a battery in these is 6 years.
Odds are you need a new battery but check it first.

FYI

http://www.e90post.com/forums/showthread.php?t=986670

Battery is charged at the jump point.
There is a glass eye on some of the OEM battery that tell you if it's
any good . The hold down clamp must be taken off to see it.

[Bmw1939]

If the battery is shot buy a new one from autozone. 200 bucks. Install it. Get an obd2 bluetooth and buy bimmer code. Register it. Done. If you think it has life left use bimmercode or bimmertool lite which will tell you the battery life and health. If shot install new one. Should last a few years minimum.

[JunkyardDogg]

I'm fine with getting a new battery, but the one I have I replaced about a year ago and registered it using inpa. Maybe I did it wrong so the battery died so fast? I'm also reading some people have issues with the IBS cable and it drains the battery. I just got a multimeter so ill test the battery tonight.

[e91Owner]

Originally Posted by JunkyardDogg

I'm fine with getting a new battery, but the one I have I replaced about a year ago and registered it using inpa. Maybe I did it wrong so the battery died so fast? I'm also reading some people have issues with the IBS cable and it drains the battery. I just got a multimeter so ill test the battery tonight.

Well if it's just a year old, it'll be under warranty if it's bad. To really determine that definitively, though, you'd need to take it somewhere like an auto parts store or Walmart to get tested after charging it. Now if after charging it, it's not reading 12V, yeah it's done.

[JunkyardDogg]

Originally Posted by ctuna

You need to get a voltmeter.
And measure both the battery voltage and alternator voltage.
If your battery was 5 volt it's probably shot.
You could try putting a long charge on it like at least 5 hours
and see how long it holds the final voltage.
Average life on a battery in these is 6 years.
Odds are you need a new battery but check it first.

FYI

http://www.e90post.com/forums/showthread.php?t=986670

Battery is charged at the jump point.
There is a glass eye on some of the OEM battery that tell you if it's
any good . The hold down clamp must be taken off to see it.

Not sure why the person who jumped my car told me 5v. I just tested it with a multimeter and it gave me 11.9V but I get absolutely no power at all so I doubt its a battery issue. I'm wondering if I disconnect the IBS cable it will work.

Originally Posted by e91Owner

Well if it's just a year old, it'll be under warranty if it's bad. To really determine that definitively, though, you'd need to take it somewhere like an auto parts store or Walmart to get tested after charging it. Now if after charging it, it's not reading 12V, yeah it's done.

I bought it 2.5 years ago and tested it myself with a multimeter and its 11.9v. I might just take it anyway to the auto store and see what they say. I actually never saw a low battery indicator on the dash either.

[e91Owner]

Originally Posted by JunkyardDogg

I bought it 2.5 years ago and tested it myself with a multimeter and its 11.9v. I might just take it anyway to the auto store and see what they say. I actually never saw a low battery indicator on the dash either.

11.9 is pretty low either way, so they can tell you definitively if it's bad.

[JunkyardDogg]

Originally Posted by e91Owner

11.9 is pretty low either way, so they can tell you definitively if it's bad.

I disconnected the ibs cable and it started!

Do I need to replace that cable or can I drive with it disconnected?

[e91Owner]

Originally Posted by JunkyardDogg

I disconnected the ibs cable and it started!

Do I need to replace that cable or can I drive with it disconnected?

Not really sure. I think in the short term, meaning driving yourself to get a new battery, no. At 11.9V, it's not surprising though, that it would send a signal that it wasn't at the minimum voltage.

[gbalthrop]

Originally Posted by JunkyardDogg

I disconnected the ibs cable and it started!
Do I need to replace that cable or can I drive with it disconnected?

Please attach photos of the IBS wires as they WERE connected before you disconnected anything, and THEN clearly indicate WHAT you disconnected.

There are THREE (3) B+ Cables from the Battery:
1) LARGE B+ Cable from BST on (+) Battery Post that goes down the front of the Battery to Outboard Transfer Point (through chassis), and then forward to Starter/ Alternator, as well as Jumpstart Terminal under hood;
2) Medium B+ Cable that goes UP, over battery, to Chassis harness and runs INSIDE vehicle to Right Side of JB (Junction Box) Fuse Panel. THAT powers everything INSIDE the vehicle, CAS Module, Radio, Instrument Cluster, A/C Blower, etc., and Exterior Lights;
3) Small B+ Cable that goes down front of battery to Inboard Transfer Point, then forward under vehicle to E-Box near Jumpstart Terminal.

Are the two 10mm T-bolt Nuts that secure battery Terminals to Battery Posts BOTH snug?
George

[JunkyardDogg]

Originally Posted by gbalthrop

Please attach photos of the IBS wires as they WERE connected before you disconnected anything, and THEN clearly indicate WHAT you disconnected.

There are THREE (3) B+ Cables from the Battery:
1) LARGE B+ Cable from BST on (+) Battery Post that goes down the front of the Battery to Outboard Transfer Point (through chassis), and then forward to Starter/ Alternator, as well as Jumpstart Terminal under hood;
2) Medium B+ Cable that goes UP, over battery, to Chassis harness and runs INSIDE vehicle to Right Side of JB (Junction Box) Fuse Panel. THAT powers everything INSIDE the vehicle, CAS Module, Radio, Instrument Cluster, A/C Blower, etc., and Exterior Lights;
3) Small B+ Cable that goes down front of battery to Inboard Transfer Point, then forward under vehicle to E-Box near Jumpstart Terminal.

Are the two 10mm T-bolt Nuts that secure battery Terminals to Battery Posts BOTH snug?
George

I pushed this clip with a screwdriver and out came the 2 wires


Actually, I did notice that when I went to remove the negative battery terminal, the bolt that secures it was loose. Can just a loose bolt cause no power? Because the terminal was still seated firmly on the post. So much that I had to pry with a screwdriver. Once I took off the negative battery terminal, THEN I removed the ibs cable. I'm wondering if I should try putting the ibs back with the bolt is securely fastened. Possible it was just a loose bolt?

[e91Owner]

A loose connection wouldn't be causing your battery to read low. But you did indeed remove the IBS connection. Is it still reading sub 12V? If so, reconnecting the IBS will likely recreate the problem, since terminal voltage is one of the parameters sent to the DME via the IBS.

[JunkyardDogg]

Originally Posted by e91Owner

A loose connection wouldn't be causing your battery to read low. But you did indeed remove the IBS connection. Is it still reading sub 12V? If so, reconnecting the IBS will likely recreate the problem, since terminal voltage is one of the parameters sent to the DME via the IBS.

I checked this morning and the battery read 12.3V. So it seems the IBS was causing the issue. Do I need to get a new negative battery terminal kit or can I just drive with the IBS disconnected?
https://www.fcpeuro.com/products/bmw...hoCNEUQAvD_BwE