hi $$ may not = quality

My dad finally got his dream, a BMW 530, bought 2 years ago.

Sweet car. I drive it as much as I can, and it MOVES!!! (Burlington VT to Montreal in 45 minutes, including the border stop apparently...)

But, he goes away on business quite often. He has just returned form a trade show (MCPX in Las Vegas) and was away for a week.

It seesm the car will not hold a charge [battery] if not run every second day. He constantly has to recharge teh battery when he goes away for a week or more.. He has had it in, serviced, replaced batteries, etc.. He even has an after market 'solar recharger' on the back shelf.. (mind you sub zero temps don't help..)

Amazing, you can spend gobs of money for a name, and still get a peice of junk (although nice supple leather, heated steering wheel, traction control, and a slew of other niceties in said 'junk'..)

Check the glove box light. Sounds silly, but my Dad had a Chrysler that would do the same thing back in the 70's. The garage swore there was nothing wrong with the electrical system. Turns out the thing was on 24/7 and killed the battery if not run every couple of days, especially in the winter.

That's exactly what happened to me as well.

Or the vanity mirror lights. I had one car where the fuel pump solinoid failed in the on position.
Ran the battery down in less than the 8 hour day. Best to check most of these yourself, don't want
to pay a mechanic $100/hour to do it. Listen to the car when it is off, do you hear a pump or fan
running. Check back in 1/2 hour and if it is still running, that is probably the problem.
Check at night to see if any light is visible inside the vehical ... and remember have fun.

probably something more complicated than that stuff. Most new cars have battery disconnect system to prevent a dead battery from some kind of constant drain such as dome light or radio being left on. My Saturn does so I would be really surprised if this bmw doesn't. One of the computers or boards probably needs to be replaced and the dealership doesn't want do it. Your dad should start contacting bmw corporate if the dealership won't make this car right.

Hmm... I dont think that the problem is in the line of BMW's. My dad has an X5 that is almost due back from its lease. He already has a new car, so it just sits there in the winter. We went outside the other day and started it for the first time in a month and it started right up. I dont know though, that just may be an exception.

Dr. Wogz

If the car is only 2 years old, I'd bring it to the dealer, because it should still be under warantee. If it's not, find a good BMW mechanic. It just might be possible that reading the CPU trouble code under the dash might tell you where it is.

Electrical problems in a car can be a bear to solve because of back powered circuitry. You will need a car schematic if you can't quickly find anything obviously wrong.

All new cars do not power down everything then you turn them off. According to my friends with beemers, there's lots of stuff that stays on, expecially the computers, however this is not enough power drain to kill a battery in a few days. I assume that the driver is not leaving a dome, dash or courtsey light on. I know that my mother-in-law has done that several times without knowing it. Some switches, especially those on the rear view mirror, are easy to bump on.

Barring this, the most likely cause is a stuck switch or a stuck relay that is drawing power even when the car is turned off.

Typical stuck stitches can be the glove box, trunk, and door pin switches.

Relays are located in a box under the hood. Head light, fog light, fan, etc.relay can stick and draw power. The relays are located in a box under the hood. It is tedious, but you can pull them and check them individually to see if they are sticking or leaking current.

Check the BMW forums for likely sources.

Bob Krech

Originally posted by stl1951
Or the vanity mirror lights.

Click to expand...

Vanity mirror got me once. Shelled out for a new battery before I realised what was up.

Thanks guys,
(Robin thanks you too!)

I should point out that he is an elecronic engineer (30+ years experinece, and runs his own company). He's looked into drain sourses, and really hasen';t fopund any./ But he will agree, that there are things that do run continuously, but shoudln't present a major drain..

He has looked at various things, and will agree, that there are some small items that do remain on. Typically, the 'spray jet nozzle warmers' (to stop teh windsheild cleaning solution spary jets from freezing..) do remain on. He does unplug hem when he goes away, along with a few other things.

The recent drain he attributes to the extra cold weather!

Originally, it was a faulty battery, but teh mechanics at teh dealership, and teh sales guys all insisted taht it was something else, so, a few electronic parts were changed out before he jumped up and down to have them just replace teh battery..

My daughter's VW Jetta did the same thing 'til I checjked the battery for draw with everything turned off...there was still about 1/2 an amp. ???

The I noticed she had been "bumped" in the parking lot in the rear end...right where the courtesy light switch for the trunk was!

Sure enough...the "bump" was just enough to leave the trunk light on!

Since he already has checked for common loads, most likely then there may be a short in a relay, which can be like looking for a needle in a haystack since they may be intermittent. Check components such as AC compressor relay, auxillary fan relay(s), power window / locks switches (which will have a tendancy to stay open due to freezing), fuel pump relay (same issue, could have a valve freeze open from moisture), climate control relays with a load VOM. All these systems can produce shorts that will put a load on the DC system and hence slowly run the battery down.

Dealerships avoid these problems like the plague becuase of the time it takes to troubleshoot. That is why they take a guess and start replacing parts.

Get this,
I bought a Lexus SC 430 last year and every time I would come to a stop I would hear a "clunk" I would accelerate and I would hear a "clunk" I took that freaking car to the dealership 8 times, had the tyranny changed, motor mounts, shocks, struts ect. Finally after having a total hissy fit they had their chief mechanic flown out from San Diego to check the car out after I threatened legal action. I was there when he looked at the car and he took the door panels off. Laying inside one of the doors was an empty Heineken bottle. I almost came unglued! To say the least I got a 100% refund.

replace the alternator. this is a fairly common problem with most cars. if you replace it and it still dies, check your battery connections, make sure nothing is corroded. the true test is, take it for a drive. a GOOD 2 hour drive, and dont shut it off the entire time. if it dies on you while you're driving, its definately an alternator. i'd take a spare one with me and a wrench so you can change it out on the fly. heh. its not hard. belt tensioner and then usually 2 bolts on the alternator and its off. just make sure all the grooves on the fan belt fall into the groves on every pully, or else you'll be in bad shape when that engine turns over. for corroded lugs on a battery, or any other corroded connections, take a dixie cup and put about a quarter inch of baking soda in it. then drizzle some water into it. just until all the baking soda is wet. then grab some steel wool, pour the baking soda on the corroded parts and let it fizzle. then scrub it good with some 000 steel wool. that works for me. if you think its the cold, try one of those gel cell batteries. they're expensive 100 dollars +, but i have first hand experience that it will start 0 degrees or 80 degrees. every time.

A friend of mines BMW did the same thing. They fixed it a week or two ago. I can't remember the exact drain source now, but there was a recall on it. You may be able to check for a recall, and if you want, I can ask here again what it was.