Ripped from a random forum but the info is the same as i told you before.
Dimming lights are normally caused by an inadequate ground wire. contrary to popular belief, dimming lights are not normally caused by a lack of power. More often thannot they are caused by an inadequate chassis ground..
Ok, this is my first post on this forum, and I am a new GA owner.. maybe I shouldn't start on this forum by posting this, but I had to after reading this thread.
Ok, first of all.. a bit of backround on me... I have been in the car audio industry for about 6 years... I did a bit of installing (I rather suck at it because I get lazy).. I am MECP certified, and I sold car audio equipment for the rest of the time. (For everyone who knows what they are talking about.. yes.. MECP is bull****, and doesn't mean anything.. but for those who don't know what you are talking about.. it means that I do know what I am talking about)
There is A LOT of bad information even in this thread that is supposed to be giving clarity. I had to stop reading on page three, so I jumped here.
I am going to explain very simply about diming lights in lamen terms so that everyone understands.. I wont even mention watts, volts, or anything have to do with Ohm's because it really doesn't matter. To a seasoned car pro, what I am saying you can easily pick apart, and say that is not how it works, but realise why I am explaining it like this.. Fundamentaly, this is EXACTLY how it works... for the purpose of explaining it without using any technical terms... this explains it just fine.
Very simply, your lights are diming because something in your electrical system is using more power than it should be, without putting in back into the system, and is making other devices starve. Your cars electricity is basically like a large loop. Every device in your vehicle that uses electricity, takes just as much as it needs, and then spits it back out to the rest of your system.
Think of this like a buffet table. Everyone is eating, and the chefs keep bringing out food. Well, then some big fat kid comes in, and eats all the food, farting real loud just like your stereo is. Well, now everyone else is starving for food, and they are getting weaker.
How do you fix this? Well a cap is def not the answer, just like the first post mentioned in this thread... and for the exact reason that was mentioned...
Do you get a bigger battery and alternator as the next step? No... no you don't.
Most installers out there will tell you I am full of **** right now, because if you do the math, a stock alternator can power your massive stereo.. that may be true.. but for 90% of you that have diming lights, that is not the case. You can go waste money on your new stuff, but that might not even fix the problem, and it is definately not necessary.
If you are running a massive 150-160 db system.. ignore this post.. but if you have an average stereo system... 2 10" Alpine type R's... 2 12" jl 12w3v2's... then I would not jump to the idea you need to replace your battery and alternator right away.
That being said.. of course make sure they are in good working order... if they are ... then try this.
MOST systems will have diming lights because the AMP is using such a large amount of electricity (like the fat kid) but is not dispursing it back in to the system allowing other devices to use it as well. Now this creates 2 problems. The amp can't just, not let electricity pass through it. It needs to dispurse it somewhere. It does so in two ways... of course through the ground, and through heat energy. It is good that is passes it through the ground, it is bad that is keeping it in the amp and dispursing it as heat.
To fix this, check your f'ing wiring. After 6 years of almost daily showing 16 year old kids why they shouldn't install their own stuff, grounds are the most common reason why people have diming lights.
"Well i cleaned the ground spot very good with a wire brush"... thats great.. glad you did that... too bad your ground is 20 feet long and 8 gauge... or.. too bad your gounding it to tin flasing that is glued on to the inside of your trunk...
There is no definate answer to where is the best place to ground your stereo. Every system is different, and every car is different. I can almost guarantee you though, that it is the reason for your diming.
My most common answers when asked why lights were diming was
1. Check your ground, make sure it is clean, tight, not open to the elements, and attached to a major groundable support structure. I have even noticed that adding a grounding strap between certain panels in the vehicle hace stopped lights from diming.
2. Check your power, and ground. Make sure that your power wire can handle your needs, and if it is barely handling what you need, step up the ground, or shorten it if you can. There is no problem is running an 8 gauge power, and a 4 gauge ground. Some installers say this will cause noise, and sometimes it can... however, that is rare, and if causes noise, then try something else.. but if it stops your diming without causing noise.. guess what... you are a genious.
3. Don't be stupid.. if you are running a 400w amp on a JL 13w7... you obviously have the damn thing cranked and it isnt working to its potential, and is causing a lot of problems. Run things how they are supposed to be ran. If you can't afford to run it properly, then don't buy it. GAIN IS NOT A VOLUME CONTROL!!!! .. I can not stress that enough.. I wont bother explaining what gain actually is, but it IS NOT VOLUME!!! yes i realise it makes things louder when you turn it up, but it also adds that distortion that loves to heat up voice coils and turn your ports into fog machines.
If all of that fails, then.. and only then.. look in to beefing up the cables on your alternator. This rarely does anything, but has worked in the past.. If that still fails then get a new alternator/battery.. or add another battery.. or whatever. If you add another batter, make sure you do it properly and use a kit / relay system. Don't just run it in series, or parallel like I think someone was mentioning early.. that is retarded.
If all of that fails... TURN IT DOWN!!!
