big three

[pat656 2]

ok so i have heard that i need to do the big three and not get a cap

i have a few questions regarding this though

i have a bmw and the battery is in the trunk, so do i still need to run the alt to batt wire with fuse? i mean stock is a 4 gauge

and since stock is 4 gauge everywhere will the big three help at all? or do i just need to buy a new battery

my car dims a lot with a small 300w system and i have a new battery and alternator

everything is grounded correctly and i run 4 gauge and 16 for the subs

Patrick

[KU40 173]

I moved this to the electrical section.

If you are getting dimming with only 300 watts there may be something wrong. What are the stock alternator and battery sizes?

With only 300 watts 4 gauge is fine.

[slim2fattycake 85]

Yup, that is really weird that 300 watts make you dim. This is more than a big3 problem. Have you had anyone check the alternator and/or battery? And make sure those ground points are sanded really well, and that they are the metal of the chassis and not something else.

[bigrank916 72]

You should do a load test on the alt. 300 watts is not nearly enough to do that.

[slim2fattycake 85]

What happens when you have the accessories and air on full blast without the music playing? Do you still get dimming?

[pat656 2]

What happens when you have the accessories and air on full blast without the music playing? Do you still get dimming?

thats how i blew my alt

i had the air radio subs windshield wipers on full and all lights on and it died

its brand new battery and alt

everything is grounded correctly and i even did a battery ground on the batt to chassis wire

the battery is really big but i dont know the size without taking it out

Patrick

[bigrank916 72]

Even though the alt is new, is it enough? Maybe with all those systems running, it cant handle it. What is the amp rating on the alt you put in? The OEM alt might not be enough. But with only 300 watts, thats sounds pretty crazy doesnt it?

[pat656 2]

Even though the alt is new, is it enough? Maybe with all those systems running, it cant handle it. What is the amp rating on the alt you put in? The OEM alt might not be enough. But with only 300 watts, thats sounds pretty crazy doesnt it?

120 amp i think, at least thats what it says on bavauto.com

[KU40 173]

No way should you be having problems with a 120 amp alternator. Something else is going on then.

The last alt may have just died because it was old and wearing out anyways, regardless of having all those things on. But if the new one is still bad, either the alternator has a factory defect or something is really pulling current other than the stereo.

[pat656 2]

No way should you be having problems with a 120 amp alternator. Something else is going on then.

The last alt may have just died because it was old and wearing out anyways, regardless of having all those things on. But if the new one is still bad, either the alternator has a factory defect or something is really pulling current other than the stereo.

that was my thought exactly, i mean the alt was 6 years old

but the car was checked over by a professional car audio installer and it was fine and like i said it has 4ga wire

to top it all off my friend has a 2000W system in his 3series (with same battery) and he has no dimming at all

[jcarter1885 995]

No way should you be having problems with a 120 amp alternator. Something else is going on then.

The last alt may have just died because it was old and wearing out anyways, regardless of having all those things on. But if the new one is still bad, either the alternator has a factory defect or something is really pulling current other than the stereo.

that was my thought exactly, i mean the alt was 6 years old

but the car was checked over by a professional car audio installer and it was fine and like i said it has 4ga wire

to top it all off my friend has a 2000W system in his 3series (with same battery) and he has no dimming at all

Getting your car checked by a supposedly professional car audio installer means nothing nowadays especially if it deals with electrical or voltage problems, take your car to someone who knows or specializes in electrical work (be smart about how you take care of your car especially if you want it to last long).

How about you get a volt meter so you can watch your voltage (Im pretty sure there is more in your car than that if its dimming, what other car audio equipment do you have in there?). Buy a digital multi meter and test amp and battery, with car on and car off. I hope when your sitting idle, you turn your system down. Do you play your system with car off alot?

[pat656 2]

No way should you be having problems with a 120 amp alternator. Something else is going on then.

The last alt may have just died because it was old and wearing out anyways, regardless of having all those things on. But if the new one is still bad, either the alternator has a factory defect or something is really pulling current other than the stereo.

that was my thought exactly, i mean the alt was 6 years old

but the car was checked over by a professional car audio installer and it was fine and like i said it has 4ga wire

to top it all off my friend has a 2000W system in his 3series (with same battery) and he has no dimming at all

Getting your car checked by a supposedly professional car audio installer means nothing nowadays especially if it deals with electrical or voltage problems, take your car to someone who knows or specializes in electrical work (be smart about how you take care of your car especially if you want it to last long).

How about you get a volt meter so you can watch your voltage (Im pretty sure there is more in your car than that if its dimming, what other car audio equipment do you have in there?). Buy a digital multi meter and test amp and battery, with car on and car off. I hope when your sitting idle, you turn your system down. Do you play your system with car off alot?

this guy is the best in my area and highly recommended, and happens to be a family friend, and i get it checked by the guy who works on my car

i will play around with the meter, since i dont have a built in volt meter in my car

and i never play it with my car off, i have seen too many of my friend's batteries die because of that

well its just the stock HU, speakers (replaced but still stock specs) and stock amp

i do rum 55W HIDs, but this was happening before i added those

i just added the subs, no other audio equipment

[jcarter1885 995]

Go buy a volt meter like most of us who didnt have one come factory and install it. Well I understand what your saying about your installer but if you want to listen to someone who cant even tell you why your lights are dimming off of 300 watts and he is supposed to be the best then that should tell you something. But its your car and not mine, so shortcut and see where it gets you but I would take my shit to BMW or someone else who is certified before the problem continues and gets worse, just my .02 but to each its own.

[pat656 2]

Go buy a volt meter like most of us who didnt have one come factory and install it. Well I understand what your saying about your installer but if you want to listen to someone who cant even tell you why your lights are dimming off of 300 watts and he is supposed to be the best then that should tell you something. But its your car and not mean, so shortcut and see where it gets you but I would take my shit to BMW or someone else who is certified before the problem continues and gets worse, just my .02 but to each its own.

i have a volt meter and a friend who is an electrical engineer, ill look at it tomorrow

thanks for the help

[Steveman09 1]

Go buy a volt meter like most of us who didnt have one come factory and install it. Well I understand what your saying about your installer but if you want to listen to someone who cant even tell you why your lights are dimming off of 300 watts and he is supposed to be the best then that should tell you something. But its your car and not mean, so shortcut and see where it gets you but I would take my shit to BMW or someone else who is certified before the problem continues and gets worse, just my .02 but to each its own.

i have a volt meter and a friend who is an electrical engineer, ill look at it tomorrow

thanks for the help

Has anyone thought he might be running a highly underrated amp?

What amp are you running?

And if it isnt underrated, maybe its bad and pulling more current then it should, I had that problem awhile back.

[///M5 2,833]

Go buy a volt meter like most of us who didnt have one come factory and install it. Well I understand what your saying about your installer but if you want to listen to someone who cant even tell you why your lights are dimming off of 300 watts and he is supposed to be the best then that should tell you something. But its your car and not mean, so shortcut and see where it gets you but I would take my shit to BMW or someone else who is certified before the problem continues and gets worse, just my .02 but to each its own.

i have a volt meter and a friend who is an electrical engineer, ill look at it tomorrow

thanks for the help

Has anyone thought he might be running a highly underrated amp?

No, not it.

If it were a raw class A then perhaps, but I am sure he'd tell us if he spent that much on it.

BTW cheap HID's can sometimes dim extremely easy. The BM'er in really working form should have no problems with what he has. Having it checked out by someone who specializes in electrical is a logical next step. DEFINITELY DO NOT buy a cap now.

[pat656 2]

im going to have it checked out soon

the HIDs dont really dim, its more the fog lights, and they are only 35W

the amp is a mono 300W Rockford Fosgate (like the p300-1 i think)

[///M5 2,833]

Interesting, not sure why you are running your fogs when it isn't foggy. Measure your voltage at the fogs and at the battery and see if they are different when this dimming occurs.

[pat656 2]

i only run them at night (b/c they are bright) and when its foggy

i went to the local Interstate battery warehouse (thats who makes my current car battery) and they checked it and the alt and stuff like that and they said everything was fine and the alt was putting out 14.2V

they said its just gonna dim a little and not to be worried, and if anything add a second battery (and they were not saying that bc they sell batteries)

[Steveman09 1]

im going to have it checked out soon

the HIDs dont really dim, its more the fog lights, and they are only 35W

the amp is a mono 300W Rockford Fosgate (like the p300-1 i think)

There ya go Fogate P300-1 is a very underrated amp, I wouldn't doubt when pushing it the lights dim a little bit!

I used to have a old Punch Turtle Shell amp that was VERY underrated and it made my lights dim with a 110A ALT.

[slim2fattycake 85]

I doubt its that under-rated.

[Steveman09 1]

I doubt its that under-rated.

Here is a review I pulled off google :

Price Paid: $200.00 from HH Greg

Year / Model Reviewed:

p3001

Summary:

I like this amp.... ive ran about 3 different combos off of this amp.... at one point i had it pushing two 12 inch memphis DVC's and and audiobahn 15 and it banged.... right now i have it hooked up to a 12inch P3 rockford and it can the sub can barely handle it.... so i dont know if i just lucked out or what but the birth certificate on my amp rates it at 1137 watts and ive blown enough subs to think its true....

Strengths:

lots of power.... tight hitting.... doesnt heat up....

Weaknesses:

having trouble finding something other than a rockford T1 Power that i can use it to power

Similar Products Used:

MTX Memphis Audiobahn JL

Seems that guys is pushing 1137watts! Thats definitly enough to dim lights....

I used to have a 3001 Punch that had a birthsheet of 680watts, so I'm thinking his is underrated as well.

What OHM load are you running it at? That makes a big difference too, ive run mine at 1-ohm before and it pushed really well, but thats under what its rated since its 2-ohms officially.

[pat656 2]

I doubt its that under-rated.

Here is a review I pulled off google :

Price Paid: $200.00 from HH Greg

Year / Model Reviewed:

p3001

Summary:

I like this amp.... ive ran about 3 different combos off of this amp.... at one point i had it pushing two 12 inch memphis DVC's and and audiobahn 15 and it banged.... right now i have it hooked up to a 12inch P3 rockford and it can the sub can barely handle it.... so i dont know if i just lucked out or what but the birth certificate on my amp rates it at 1137 watts and ive blown enough subs to think its true....

Strengths:

lots of power.... tight hitting.... doesnt heat up....

Weaknesses:

having trouble finding something other than a rockford T1 Power that i can use it to power

Similar Products Used:

MTX Memphis Audiobahn JL

Seems that guys is pushing 1137watts! Thats definitly enough to dim lights....

I used to have a 3001 Punch that had a birthsheet of 680watts, so I'm thinking his is underrated as well.

What OHM load are you running it at? That makes a big difference too, ive run mine at 1-ohm before and it pushed really well, but thats under what its rated since its 2-ohms officially.

oh wow that would make sense then, i just hope i dont blow my 2 rockford punch P1 12" subs

im running 2 ohm

[slim2fattycake 85]

Edit:

Just read that again.

If this amp is a class a/b amp then maybe the current draw from the battery is about the same as a class d amp rated for double that of the A/B amp.

[KU40 173]

The new punch amps aren't as underrated as the old ones. Back in the day of the old gray waffle iron heat sinks they were underrated by nearly 100%. But not anymore. Rockfords have always also been a bit current hungry. Yep, I just looked it up, and as per Rockford's website, that amp is only 65% efficient because it's a class A/B. So you're pulling about 500 watts from the electrical system. Are you clipping the hell out of it too?