Bigger Alternator?

[brods525]

So I just bought my 525i and it has a very nice stereo. The guy said that if you turn the stereo up loud and have the lights on and stuff that the car will lug and it loses RPM. So I tested it and sure enough, with the lights alone. I checked at the local AutoZone and they had a 140 amp, which I already have. Is there a bigger alternator for my car??

[boone.msi]

Please list what audio components your using and if any CEL's or other problems are accuring, i don't believe this is a charging problem...

[brods525]

I have a JVC Headunit that has a LCD screen, I'd say about 3.5 inches and then i beleive stock speakers with 2 12" subs one Rockford Fosgate than another that I am not sure which brand then it has a 1,000 watt Kenwood amp. I already have a BMW 140 Amp Alternator... What could it be? The check engine light came on and the car lugged real bad tonight when i took it out... but only when there is more than one thing going at a time, its fine durring the day.

[attack eagle]

1: nothing you have is big enough to cause a problem. (though running differnt subs is never a good ideal)

So you can eliminate the notion that your alternator is too little, and start figuring out WHY you are having the problem.
Test the battery. test the alternator.

[brods525]

I think that I'm going to take the one sub out thats not RF. I will have the alternator tested; the battery is brand new.

[robmpulse]

you need a capacitor.......

[attack eagle]

bull

[Analog]

you need a capacitor.......


No. Your alternator is most likely fine. My guess is the guy ran his battery down, killed it, and just fast charged it, so now it won't hold a charge. I am running an ED 15, on a 1200 watt amp which pulls ALOTof current, and I have zero problems with a new battery.

[attack eagle]

;) you mean your AMP pulls a lot of current...

[Analog]

argh. yes. lol.

[brods525]

Wow, everyone is alot of help. :)
I went to have the battery tested and they said its fine and that IT IS new.
The alternator was fine too he said, he didnt test it but it was putting enough amps back in. He told me to have the wiring checked, and make sure the grounds are ok. I am scheduling a diagnostics test soon. Oh and what grade of gas do you all put in your 5-Series?
Thanks

[attack eagle]

Monitor your voltage when the problem occurs.

[IamCatman]

You have a cheap amp ...a capacitor might be a 'patch'. I have a 1000W (real watts) amp in a Miata with the stock charging system and have NO problems.

>^..^<

[brods525]

Monitor your voltage when the problem occurs.


How do I do that when it only happens when I drive the vehicle?
Sorry, I am only 17. I dont know NEAR as much as all of you.

:P

[atl530i]

How many amps are in the car? Just 2?

Like it has been said before, it is not a good idea to run 2 different subs. What model amp(s) are you running? Check all your connections.

With the car running, check and see what voltage is going to the battery. Around 13.5 to 14.4 should be going to the battery. Just a thought but worth a try. Get a multimeter if you do not have one, they are a lifesaver with these cars, period. Did the Autozone guy do that??

As for gas grades, atleast 89 but 91 is better. I forgot what compression your car has, but the higher the compression, the higher gas grade you need.


You have a cheap amp ...a capacitor might be a 'patch'. I have a 1000W (real watts) amp in a Miata with the stock charging system and have NO problems.

>^..^<

+1

[Felixdacat]

Get a capacitor. If your lights are dimming, your amp is drawing too much power. You will fry your alternator. I am running two alpine 12" type R's, Infinity Kappa perfects in the front and rear, and I have two amps. A mark Antony Gspot 2500watts pushing the 12's, and a old school California Profile running the fronts and rears. I have one 5mf capp set up for the sub amp, and my headlights still dim just a little. Get a Capp.

[IamCatman]

Get a capacitor. If your lights are dimming, your amp is drawing too much power. You will fry your alternator. I am running two alpine 12" type R's, Infinity Kappa perfects in the front and rear, and I have two amps. A mark Antony Gspot 2500watts pushing the 12's, and a old school California Profile running the fronts and rears. I have one 5mf capp set up for the sub amp, and my headlights still dim just a little. Get a Capp.

The reason a "cap" works with cheap amps is that the amp mfg's cut corners on the power supply and didn't include as much 'capacitance' as the amp really needed. So ...a "cap" is a patch ...and if it works ...you know you have poor quality amps. Running quality amps I have NEVER had a need for a cap.


I have one 5mf capp set up for the sub amp, and my headlights still dim just a little.

No wonder ....5mf is a VERY small capacitor.

>^..^<

[attack eagle]

doesn't one of the OBC tests let you monitor voltage if you don't have a multimeter?

I mean if the car is almost stalling, lugging etc you should see enough of a difference to know what the heck is up, even if it isn't directly off the battery.

[brods525]

How many amps are in the car? Just 2?

Like it has been said before, it is not a good idea to run 2 different subs. What model amp(s) are you running? Check all your connections.

With the car running, check and see what voltage is going to the battery. Around 13.5 to 14.4 should be going to the battery. Just a thought but worth a try. Get a multimeter if you do not have one, they are a lifesaver with these cars, period. Did the Autozone guy do that??

As for gas grades, atleast 89 but 91 is better. I forgot what compression your car has, but the higher the compression, the higher gas grade you need.



+1
No, there is only 1 amp.
2 12's.


And no, my lights dont dim. The car just luggs and puts then it will get back up and go. But tonight it didnt do anything, maybe because I havent really driven it much today. :)

[boone.msi]

To tell you the truth im quite stumped. I am 99% sure it is not your audio components, that 1000w kenwood is realisticly less than 500w(more like 250w) What power rating are your subs? You could be under powering them which would force alot of stress on your battery, but not enough to lug-down your car.

Also, you never ever need to get a capacitor, its a scam for your money and acts like a shitty battery. When the capacitor empties it puts twice the stress on your alternator and battery.

Have you disconected your amp to see if the problem continues without it? Have the amp disconected for about 2-3 days and see if your car lugs down.

[brods525]

To tell you the truth im quite stumped. I am 99% sure it is not your audio components, that 1000w kenwood is realisticly less than 500w(more like 250w) What power rating are your subs? You could be under powering them which would force alot of stress on your battery, but not enough to lug-down your car.

Also, you never ever need to get a capacitor, its a scam for your money and acts like a shitty battery. When the capacitor empties it puts twice the stress on your alternator and battery.

Have you disconected your amp to see if the problem continues without it? Have the amp disconected for about 2-3 days and see if your car lugs down.
I thought about disconecting it. I will and hopefully that will give me some answers. Thanks alot.... I still love my car, even though its being a pain in the ass.

[BigM62]

I use a Batcap.

[Grim Reaper]

Monitor your voltage when the problem occurs.

+1

weak voltage regulator will give the symptoms you describe

use the test function in the OBC to monitor its output

[brods525]

+1

weak voltage regulator will give the symptoms you describe

use the test function in the OBC to monitor its output


i'm totally new to this think so....
first: how hard is it to get a voltage regulator and what does it do?

second: what the hell is the OBC?

[Grim Reaper]

Hey no problem. The voltage regulator is the item that keeps the electical output delivered stable and smooth given demands upon the electrical system.

You can view the voltage and its stability via the On Board Computer - OBC

Read this, its very helpful -

http://bmwe34m5.com/node/231

Hope this helps

[brods525]

Yes, you are being VERY helpful.
It totaly makes sense if that is it.
I hope it is so that I can be done with all this shit....
I dont have the OBC though, just the normal temp, date and time.

[brods525]

I unplugged my amp today, and my car is fine. The check engine light is on and thats it.