I'm running a Kenwood bridged, puts out about 480 watts. I notice that my lights are slightly dimming when the bass hits. It's not real bad but is there anything I can do to fix this aside from getting a new alternator? I did not run the in line fuse from the battery since the amp has a 40 watt fuse on it. I am using 8 guage wire for the power, do I need to go to 4 guage? The amp has plenty of power, it's running a 12".

 

First off and most important, Put that inline Fuse on your system no more than 18" from the battery, preferably as close as you can be. This is protection in case of a short in the wire going back to your amp which could result in some serious damage! The fuses on your amp only protect your amp, not your vehicle!

You probably do not need a new alternator, The alternators put out enough charge to handle that amp.
I would recommend starting with The Big 3 as described here...
THE BIG 3

By performing a proper big 3, your dimming shoudl go away. In a previous vehicle I was running over 1100 W with standard battery and alternator (much more undersized that what we have) with no noticable dimming when I performed this upgrade.

Hope this helps.

 

Thanks Rider69, the inline fuse will be going in this weekend! I'm having trouble finding a 40 amp blade fuse, that's why I didn't wire it in yet. The kit I bought came with a 30 amp fuse. I'll try the big 3 this weekend as well, again thanks for the input.

 

Thank you for not slandering this with "add a cap" or " get the bigger alternator" I'll have to make sure I put you on my "in the know" list



Thanks rider69!

 

ryanbeal, what kind of fuse holder do you have? when you say blade fuse, I am just curious what kind of fuse that is that you need so I can possibly help you find one. Is it an ANL type fuse or a glass fuse? I get most of my stereo wiring parts from Knukonceptz.com. The quality is excellent and the stuff is very nicely priced. They have fuses and anything else you might need to wire up your stuff.

Frostby...I once fell for the "you need a cap". Until I did some research of my own and found that caps are basically useless if your electrical system does not have the cajones to keep up with your system in the first place. It is just an extra strain on your system, something else that needs to be charged.

 

Rider69 it's an ANL fuse not a tube fuse. Just like in our fuse box but not the micro size. I can find 30amp fuses all over the place but not 40amp. I was hoping to pick one up locally. I need to check at a stereo shop, might be my best bet.

 

Though I'm a HUGE fan of the big 3 upgrade, I'm not sure if a big 3 upgrade will help. The ideal of a big 3 upgrade is to match the current flow in both positve (power) cables and negative (ground) cables. You mention that you have an 8 guage power cable from your amp. The stock big 3 cables are at least 8 guage already. Actually, If I remember correctly they are 4 guage except the one small ground from the battery to the firewall (I don't know why I can't remember this, I just did mine this past weekend).

I would get a deep cycle battery (such as a optima yellow top) and see if that remedies your problem. I understand these batteries can be a bit expensive to most people, but I believe they are well worth it.

By no means add a cap...THEY ARE WORTHLESS! A HO alternator would be LAST resort, and that's for guys drawing HUGE power from multiple amplifiers and need the added amperage draw from the alternator.

Also, get that in-line fuse installed!!!! As before mentioned, that is very important and can't stress that enough.

 

I was thinking they are all 8 gauge. I dont remember seeing anything bigger than that. I dont think they would use 8 from the batt. to firwall then switch to 4 gauge either.

Even though he has 8 gauge from the batt. to the amp, and all the stock wires are 8 gauge, you have to remember that there is much more stuff running through those wires. Pretty much everything electrical in the truck runs through that little 8 gauge ground wire from the frame to batt. When you have a decent sized amp, along with everything else-that 8 gauge just isnt efficient enough. Car makers put in a wire big enough to support all the stock electrical devices, and not much more. They dont plan for big amperage stereos to be added. And even though you may have a factory option HO alternator, the auto maker isnt going to use big enough wire sufficient to run everything that alt can. Just enough for the stock stuff.
They are cheap. "why run nice big wire that can support our big alternator when we can save a few pennies and run wire just big enough to work" is probably what they say
This is why running a new ground at the least can make a huge difference.

As you suggested though, a nice battery can work wonders too.

 

Remember that the alternator supplies voltage for ALL accessories while the engine is running. Changing batteries will have absolutely no effect in that instance. To see if you have charging issues, after dark, park in front of a garage door or some such thing where you can see the intensity of your headlights perfectly well. With the engine running and with normal accessories running and your audio system going full blast, shut off the engine. Take careful note to see if your lights get dimmer or brighter. They should get dimmer. This indicates that your alternator is charging more than the 12V of the battery and when you shut off the engine and the battery is the source of voltage, the lights should dim. If your lights get brighter, you have a problem. This indicates that the battery has more voltage than the alternator is producing, which is not good. If that were to be the case, you may have an alternator on the fritz, or some wiring issues.

 

If they are 8ga, then yeah, run a 4 ga from amp to the battery and do a big 3 upgrade with 4 ga cable. Add the battery and you should be good to go!

 

Yes and no. On quick, sudden bass notes, your alt wont always provide all the current your amp is demanding right away, and that big current draw will make the battery discharge a little. Your electric devises are going to try to get that current they need, and what is the first place besides the alt. (which is already pumping away on that hug @$$ bass note) that they can get that current? The battery. So yes, it does has some effect.

But a second battery....yes, thats pretty much worthless when you have your car running. But very, very nice for tunes w/o the engine running.

 

I agree with what you say. What I should have worded it to say is that if you get to the point that something like what you describe is happening, the issue needs to be addressed. If someone is willing to install a system that, when combined with normal functions like turning on headlights, creates demands enough to "outdraw" the alternator's capabilities, then they should be willing to fork over the bucks to alleviate any such thing from happening by having an alternator with the proper capabilities. You can install capacitors and deep cell batteries and make a difference in one way or another, but I believe the answer lies in the alternator and proper cabling and connections. This is not rocket science, but people seem to be flabbergasted to learn that a vehicle's electrical system does have limits, and if you exceed those in some way, SH*T happens, either quickly or eventually.

 

Has anyone who has done the "Big Three" got any pics of the install? The link no longer has photos attatched. I was wondering how the pos alternator to the pos battery went. How would this change affect the vehicle warranty?

All great info since I will be installing a MTX Thunder895 as soon as it gets here!
Dave

 

I've got pics of my big 3, but I cant add pics to my gallery for some reason. If you want them, send me an email and I'll send them to you.

EDIT: Pics added to my gallery.

 

brypink2

What guage did you use for the big 3? Do I have to get it at a stereo shop/internet or can I get something comparable with connectors at a local store? Nice install by the way!