SLOW BATTERY DRAIN

Wil · Post by **Wil** » Wed Feb 10, 2010 9:07 am

Like other members in this post I have been chasing a slow drain of battery when the car seats for a few days.
I should mention that I have a brand new battery, so I know is not the battery, and no other aftermarket accesories like amplifiers,antena boosters ,etc.
This is what I have got so far,
Using a voltmeter I checked all fuses to see witch one is drawing power. The only one drawing is fuse 5 (8a) the one that energizes the interior light, clock , lock motors ,etc
I think it should only draw from 0.4 to 0.6 v ,(I have an analog clock) but is reading 1.2 v , that is double.
I also notice that when you remove the fuse and put it back on I can hear a click inside of driver door,
is that normal?,
can it be the solid state timer acting up?
I read in the FAQ for lock motor repairs that Allan had a problem were the timer was energized all the time , can that be the problem?
Any help is appreciated
Thanks
Wil

grumpsjr · Post by **grumpsjr** » Wed Feb 10, 2010 10:51 am

Sounds like a good possibility - does the interior light go off? You should also check the trunk light to make sure it's going off as well.

Good luck,
Brian

On Wed, Feb 10, 2010 at 6:07 AM, Wil <sietor@optonline.net (sietor@optonline.net)> wrote:

Like other members in this post I have been chasing a slow drain of battery when the car seats for a few days.
I should mention that I have a brand new battery, so I know is not the battery, and no other aftermarket accesories like amplifiers,antena boosters ,etc.
This is what I have got so far,
Using a voltmeter I checked all fuses to see witch one is drawing power. The only one drawing is fuse 5 (8a) the one that energizes the interior light, clock , lock motors ,etc
I think it should only draw from 0.4 to 0.6 v ,(I have an analog clock) but is reading 1.2 v , that is double.
I also notice that when you remove the fuse and put it back on I can hear a click inside of driver door,
is that normal?,
can it be the solid state timer acting up?
I read in the FAQ for lock motor repairs that Allan had a problem were the timer was energized all the time , can that be the problem?
Any help is appreciated
Thanks
Wil

1978 520 - 1980 528i

Post generated using Mail2Forum (http://www.mail2forum.com)

Lenny D. · Post by **Lenny D.** » Wed Feb 10, 2010 2:16 pm

I would bet on the driver's emergency lockmotor release. Although my observation is that a click after the motors are energized (either direction) is normal (in that mine does that and I have no battery drain).

PITA troubleshooting 101 says disconnect the mechanism in the door. See if the drain stops.

Wil · Post by **Wil** » Wed Feb 10, 2010 3:13 pm

Thanks Brian,
trunk,dome and glove compartment lights go off when closed
Thanks Lenny,
Can I disconect the mechanism without taking the door panel off? or removing fuse?,probably not

Lenny D. · Post by **Lenny D.** » Fri Feb 12, 2010 3:58 am

I'm not sure but I don't think so.....unless you feel like tracing the wiring harness to see if it meets another connector somewhere before the fusebox.

Also, read my post here for a tip on battery drain.

Wil · Post by **Wil** » Mon Feb 15, 2010 11:02 am

OK, this are the news
I removed the fuse with the power draw at the fuse box,to keep battery from going dead. but yesterday after car seating at the garage for two days, dead again.AHHHH!!!!!
Then I tested the draw at the battery from the post to terminal and I have over 1 amp there (don't know exactlly how much over because my meter dont go over 1 amp) ,good size spark.
So the interior lights/lockmotor fuse is not the problem now.(fuse still off)

Ok, so I figure that maybe something wrong with alternator (diodes) so I disconected the alternator and I still have the draw,that checks ok at the alternator. theres something else concted to the positive terminal (electric windows I think) so I disconected that too , but the draw still there.

Now, this is my question to the experienced guys,
What else can take power direct from the battery without going through the fuse box, that is not a bad alternator or the electric windows???????
Thanks
Wil

grumpsjr · Post by **grumpsjr** » Mon Feb 15, 2010 11:03 am

How about the radio, if it's aftermarket?

On Mon, Feb 15, 2010 at 8:02 AM, Wil <sietor@optonline.net (sietor@optonline.net)> wrote:

OK, this are the news
I removed the fuse with the power draw at the fuse box,to keep battery from going dead. but yesterday after car seating at the garage for two days, dead again.AHHHH!!!!!
Then I tested the draw at the battery from the post to terminal and I have over 1 amp there (don't know exactlly how much over because my meter dont go over 1 amp) ,good size spark.
So the interior lights/lockmotor fuse is not the problem now.(fuse still off)

Ok, so I figure that maybe something wrong with alternator (diodes) so I disconected the alternator and I still have the draw,that checks ok at the alternator. theres something else concted to the positive terminal (electric windows I think) so I disconected that too , but the draw still there.

Now, this is my question to the experienced guys,
What else can take power direct from the battery without going through the fuse box, that is not a bad alternator or the electric windows???????
Thanks
Wil

1978 520 - 1980 528i

Post generated using Mail2Forum (http://www.mail2forum.com)

Wil · Post by **Wil** » Mon Feb 15, 2010 11:15 am

Radio takes power from cigarette lighter, and that goes through fuse box.
I checked that already
Thanks GRUMPSJR, but that is not it

Lenny D. · Post by **Lenny D.** » Wed Feb 17, 2010 2:00 pm

Wil wrote:"What else can take power direct from the battery without going through the fuse box..."
Wil

What else can take power direct from the battery that is not supposed to is the question you should be asking. You have to think outside the electrical box.
A 'good sized spark' is a pretty good power draw and I'm not surprised at all your battery winds up dead in short order.
So....thinking outside the box means things like your ignition switch. I had one fail that allowed the switch to remain in the 'on' position with the key in my hand. All the accessories had power in that situation.

"I also notice that when you remove the fuse and put it back on I can hear a click inside of driver door,
is that normal?,
can it be the solid state timer acting up?
I read in the FAQ for lock motor repairs that Allan had a problem were the timer was energized all the time , can that be the problem?"

I mentioned the emergency door lock system and after rereading your first post that is an enthusiastic YES!.

Other things - flashlight in the glove box? (And wiring)
The only way to pinpoint the problem is to methodically take one thing at a time out of service (disconnect them at their source) to see when the voltage draw stops. PITA, yes, but........

Good luck and keep us posted, we all learn by everyone's problems and eventual solutions.

Wil · Post by **Wil** » Wed Feb 17, 2010 6:13 pm

Thanks Lenny for your words of encouragement , this is a real PITA
I got that the click on the door is normal, based in your comment.
I have draw at battery terminal even when I remove the fuse that feeds the locks , so I know is not the locks
I also pulled up on that inertia switch by the glove box , just in case but no change
I haven't check the flashlight docking, I dont know if that goes trough the fuses but I will do that next

Thank you very much for all your help,

Lenny D. · Post by **Lenny D.** » Thu Feb 18, 2010 2:25 am

Here is a wiring diagram of what is controlled by Fuse 5 (and some of Fuse 6). Driver's seatbelt switch feeds the seatbelt warning timer (and is also fed from fuse 6), the rest is obvious with switches that control lights.

After searching the rest of the wiring diagram, only the window relay, alternator are not fused. There is a note saying the window motors have internal circuit breaker protection.

What happens if you pop the window breakers on the lower cowl?
What happens when you remove all the fuses? (And install them one at a time?)
If your problem is still there with no fuses installed and the window breakers disconnected then the alternator is the only device connected to the battery bus.

Pierre · Post by **Pierre** » Mon Feb 22, 2010 12:29 am

With the battery fully charged, disconnect the negaticve cable. Make sure the ignition is off.
Touch the negative cable to the battery and listen for a relay click. Seperate the cable and touch again. Place you hand on the relays in the fuse box and feel for any of them being triggered.
Best of luck.

1st 5er · Post by **1st 5er** » Tue Feb 23, 2010 12:39 pm

Lenny D. wrote: Good luck and keep us posted, we all learn by everyone's problems and eventual solutions.

X2

Inquiring minds want to know.

Wil · Post by **Wil** » Wed Feb 24, 2010 7:07 pm

Sorry , no news yet, little time off
Still working on it, I will keep you guys posted
Wil

Tomslide · Post by **Tomslide** » Fri Feb 26, 2010 1:48 pm

I tested the draw at the battery from the post to terminal and I have over 1 amp there

That's an issue. Disconnect and clean your battery post and terminal.

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