I have dimming and rpm drop...what should I do

[backtofront001 10+ year member]

I have a 12" RL-P being powered by a Nine.1 at 1 ohm so it is recieving 1000 watts. When I play a song that hits pretty hard, my lights start dimming even when I am moving and when I play a song that hits super hard my lights start dimming and my car has slight rpm drops even when the car is in motion (they are like hiccups). I think my stock alt is 140 amps and I have stock battery. I have 2006 BMW 325i and I dont want to kill the electrical system or any components because it will cost me a fortune to fix them. I can't do big 3 because my battery is in the trunk and the dealership might void my warranty because of that. What should I do????

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[thatsgonnahurt 10+ year member]

headlight dimming happens! after a night of playing tunes will your car start the next day? a 140 amp alternator can handle a 1000 watt system!

 

[Johnny Drama 5,000+ posts]

Is an '06 so it shouldnt have the RPMs drop. Maybe take it somewhere and have the battery checked to see if its a good battery. Definatly check the manufacture specs on how big the alt is.

 

[backtofront001 10+ year member]

Is an '06 so it shouldnt have the RPMs drop. Maybe take it somewhere and have the battery checked to see if its a good battery. Definatly check the manufacture specs on how big the alt is.

The alt is 140 amps. By RPM drops i mean, like one day i had the car on cruise control and the music was loud the bass was hitting hard and the car started having small hiccups. It was wierd.

 

[backtofront001 10+ year member]

headlight dimming happens! after a night of playing tunes will your car start the next day? a 140 amp alternator can handle a 1000 watt system!

Yes it starts

 

[Johnny Drama 5,000+ posts]

The alt is 140 amps. By RPM drops i mean, like one day i had the car on cruise control and the music was loud the bass was hitting hard and the car started having small hiccups. It was wierd.

Sounds like the system is using all of the reserve capacity on the alt, and still draining the battery. Honestly, this issue is probly something you will want to take to a respectable shop.

 

[backtofront001 10+ year member]

Sounds like the system is using all of the reserve capacity on the alt, and still draining the battery. Honestly, this issue is probly something you will want to take to a respectable shop.

Would a capacitor help? I have a friend who has 2 L7's 1600 watts in a 2005 A4 and he doesnt have any problems. He has caps and all that. Stock Electrical

 

[phantom240 5,000+ posts]

yeah... get like a 2434532 Farad cap. That should do it!

But seriously... thats not a good thing and in your case a cap would make life **** for ur electrical system.

 

[Johnny Drama 5,000+ posts]

Would a capacitor help? I have a friend who has 2 L7's 1600 watts in a 2005 A4 and he doesnt have any problems. He has caps and all that. Stock Electrical

I highly doubt a cap would help you. All I can do is strongly suggest you take it to a reputable shop.

 

[backtofront001 10+ year member]

I highly doubt a cap would help you. All I can do is strongly suggest you take it to a reputable shop.

Allright thanks I will do that

 

[backtofront001 10+ year member]

I highly doubt a cap would help you. All I can do is strongly suggest you take it to a reputable shop.

Wait, one last question before I take to shop. Could a bad Ground or smaller ground wire be the problem?

 

[Johnny Drama 5,000+ posts]

Wait, one last question before I take to shop. Could a bad Ground or smaller ground wire be the problem?

No, that would be a problem if your system cut in and out. This is an electrical issue though.

 

[backtofront001 10+ year member]

Ok. Could this be it...I didn't do a wire from battery negative to chassis

 

[backtofront001 10+ year member]

Bump

 

[j3bus2k3 5,000+ posts]

You could do it but I wouldnt count on it to solve your problems. For reference, I'm running 1100W RMS off a 100A alternator with an upgraded battery ground and I do not get dimming or RPM drops. As jntar said, take it to a reputable shop to have some tests run...