525i Wagon Power Drain

[OhioTouring]

I was hoping to not have to post this question!! I have poured through all of the posts I could find on this subject, but I am stumped.

The problem is this: After a couple of days sitting, the car needs a jump start. I put in a new battery (Duralast from Autozone), and the same thing.

The last few days I have been slowly testing things out using all of tips on this forum.

Going by Shogun's post, I put my Fluke Series 87 meter in line with with the negative cable/battery post. I let things sit for about 10 minutes and the draw is around 27.9 mili amps. I went removed every fuse / relay from the
1: Power Distribution Box
2: Electronics Box(E-box)
3: Auxillary Relay Panel
4: Rear Power Distributio Box

Here is what I found.

1: When I removed Fuse 20 the draw dropped by 4.5 mili amps
2: When I removed Fuse 36 the draw dropped by ~3 mili amps
3: When I removed the GM all power draw went away - 0 milli amps
4: When I open a door the draw goes to about 140 milli amps
5: Tested to see if the hood switch had any impact on the draw since I had it open, but it did not.

When I put the GM back in I had to reconnect the neg battery terminal to get power back to the car.

The only things I did not remove are the ABS control module, the DME control Module, and the Cruise Control Module connections in the E-box.

Everything on the car works as it should.

So, with less than 30 milli amps being drawn why does the battery loose it's top charge?

Thanks in advance for your help. This one is really wierd.

[winfred]

under 30 mil amps is normal draw, there may be something else drawing randomly or you are on the wrong scale or something and it's drawing 279 mil amps (almost 1/3 of a amp)

[OhioTouring]

under 30 mil amps is normal draw, there may be something else drawing randomly or you are on the wrong scale or something and it's drawing 279 mil amps (almost 1/3 of a amp)

On the meter, there is a terminal for 6mA to 400mA, and one for currents above 400mA. I was in the 6mA-400mA terminal and the reading on meter was 27.9 and the notation next to the number was mA. So I think the meter was setup right.

Very strange.

Could it be a bad Fuseable link that is right off of the positive cable?

[winfred]

i doubt it, i have had in the past draws that would come and go, glove box lights and aftermarket accessorys are the most common draws i track, it it was a e30 i could point you at one that most people can't find but i don't really have any e34 special odd draws



Very strange.

Could it be a bad Fuseable link that is right off of the positive cable?

[stilljester]

Have you tested your alternator to verify it is in fact charging the battery?
Have you load tested the battery to verify it is in proper working order

[OhioTouring]

Have you tested your alternator to verify it is in fact charging the battery?
Have you load tested the battery to verify it is in proper working order

No, I have not specifically performed a load test on the battery or tested the alternator.

Any tips on performing these tests?

[stilljester]

No, I have not specifically performed a load test on the battery or tested the alternator.

Any tips on performing these tests?

First thing you should do is download the Bentley Manual - its a great resource for this sort of thing....

Take your multimeter and measure the voltage across the - & + terminals on your battery. (Car off) What do you get?

Now with the car running measure between the positive terminal and ground again. What do you get?

[Spasso]

A fully charged battery with engine off should be 12 to 12.8 volts.
With the engine running the voltage should be 13.8 to 14.6 or thereabouts.

To do a load test the battery must be fully charged. The load test determines how many AMPS the battery can deliver. "Starting load". I had to take mine to the auto parts store to have it load tested.
The battery was less than two years old and would take a full charge for a while but delivered nearly zero amps due to shorted plates. The shorted plates were from the water in the battery freezing during the last bad cold snap and warping the plates hence the short.

[DanQ]

I had a problem with my touring and the bad wiring harness in the tail. The alarm would go off randomly because there were some shorted wires telling it that the lid had opened. This was while the car was parked at work. No movement. Also had the interior lights going on and off randomly due to the same problem.
Perhaps you have a similar issue? Have you checked/changed the rear wiring harness?

[OhioTouring]

I'll test the battery with the car running and with it off and see if there are any issues there.

If not, I'll be off with the battery to have it load tested.

I have not replaced or messed with the rear harness. Thinking about things a bit more. I do have a drivers side rear brake light, that intermittently throws me an error. The socket is rusted a little I think. That's the only thing wierd in the rear!!

Need to figure it out soon. Everytime I leave it at the Airport on trips, I have to carry my Portable Jump Starter :)

[Spasso]

Make sure the water level is up where it should be in the battery before you do anything else. The plates in the battery should never be exposed to air when in use. It ruins them.

Placing a charge on a battery that is low on water will fry them too.

[OhioTouring]

I measrued voltage across the terminals first thing this morning. It measured 11.97 volts. Then with the car running, the voltage read 14.2. So based on what the Bentley manual says it appears the alternator and regulator are ok.

I am going to put another new battery in.

This all started after I let the car sit over most of the winter last year. The battery was dead, so I figured it was a good time to put a new one in. So, about a year ago, I put a new Duralast in. That's when I started noticing the drain. It is possible that it has been a bad battery all this time. If so, Arrrrgggghhh. !!!!






Take your multimeter and measure the voltage across the - & + terminals on your battery. (Car off) What do you get?

Now with the car running measure between the positive terminal and ground again. What do you get?

[Qsilver7]

If you got a Duralast 49 D or 49 DL...you have a 2 yr free replacement 5 yr pro-rated warranty. So if the battery is defective...you can get a free replacement since you are still within the 2 yr period.

I believe Autozone should have your record still on file, too. At least they take personal info here when you purchase a battery...and can call up the info to see when you purchased.

[attack eagle]

shoot, they swapped me from a 48 to a 49 dl for free despite no record... the thing was obviously defective and would give you one shot at starting after sitting overnight, and if you left anything on for more than a couple of minutes... no start.

Since swapping I have had 0 issues. I'd for sure start with the possibility that the battery is bad.

[OhioTouring]

A quick update. I took the battery back to Autozone and they did a load test. It was definately bad. They gave me a new one free because it was within the 2 year warranty.

The new battery has been in the car for the last 2 weeks. No problem starting after several days sitting.

I want to thank everyone who posted ideas, thoughts and suggestions.

[attack eagle]

Glad that resolved your issue.