I have two questions for everyone here:

1. Does an aftermarket head unit draw more power from the car to the amp than a stock one?

2. Would a bigger cap or better alternator be better to stop the headlight dimming?

I have a Power Acoustik 900 Watt amp and a 1.5 farad cap right now, but my head lights just started dimming A LOT when I got my AVIC-D3 installed and they didn't do it when I had the stock HU in. I am also running a Fosgate 4 gauge wiring kit to the amp and cap. It drives me crazy when I turn the volume up past about 15 or so. The car is an '08 and I have heard the factory alternator is horrible, but I don't know if there is an aftermarket one available yet, or if that would even fix the problem. Maybe a better battery would help? Any help you guys could give me would be greatly appreciated.

 

The cap isn't the problem. A 1.5 farad is plenty for your 900 watt amp. Most aftermarket HU will draw more power than a stock one. The internal amps are always larger.

Your weak spot is the alternator. A deep cycle battery could always help but it would only mask the real problem for a while. Same as a larger cap. If you want a larger cap send me a PM.

 

wuts ur amp powering?

 

2 Kicker CVR 12's

 

Hey Serious, do you know if anyone makes a better alternator for the 08's yet? I tried searching for a few minutes but couldn't find anything.

 

i dont think an aftermarket head unit will cause your headlights to dim. it is only drawing 5-7 amps MAX. your head unit will, however, provide a better signal to the amplifier for the subs, thus, providing you with a more "powerful" output of the amplifier. the amplifier will only produce what it is told to produce. IF you have a better signal going to the amp, it will be putting out more power.

now on to your questions...

1. Does an aftermarket head unit draw more power from the car to the amp than a stock one?

i dont think you phrased this right...as stated above, it will draw slightly more current only to provide it to a signal for the amp to receive. it will not pull enough to dim your lights. dont understand?? disconnect the subs and turn it up past your volume level you stated it started dimming. i will bet it doesnt dim anymore. still does it??? you have another problem.


2. Would a bigger cap or better alternator be better to stop the headlight dimming?

i had a 180amp alternator in my mini truck for SPL competitions. my lights still dimmed at idle.

make sure your CAP is charged. sometimes people dont know about charging a cap correctly. a CAP will store energy and it will be released from the cap instead of "taxing" the alternator. this is why your lights dim. the alternator is unable to keep up with the demands of your amplifiers requirements. you may be trying to pull 40-50 amps of current from the alternator along with the required 30 amps the car needs to run the lights, ignition, fuel pump, headlights, blinkers, dashlights, brake lights, ECU, coils, etc...catch my drift??

an alternator will only provide a certain amount of amperage at idle. typically, the engine should be running at about 2000rpm to achieve max alternator output, unless you can adjust the voltage slightly. i had an adjustable voltage regulator that I would set for the car. i set it at 15.2 volts for competitions. why?? wont that hurt your car?? no, when an electrical device is on, it is using that power and never really seeing a true 14.4volts it should. (this was a way of "cheating" legally during comps...) there are many more things i could get into, as i was a very serious competitor in Sound Q class and SPL class.


a bigger battery will only hide another problem. it may help temporarily, but it wont "solve" the problem. a battery will act as a buffer for the alternator and pull current(amps) from there instead. this is usually the cheapest route.


IF it were me, i would check to see the age of the battery. get a new one if it is over two-three years old. next i would check the CAP. see if it is fully charged. this will require a test light, 12v battery, and a meter. be careful, this thing is now loaded with a whole bunch of volts and no where to go. it WILL short and cause a bunch of pretty sparks....dont ask how i know... .

lastly, IF all else fails, check the amperage on the alternator. if it is a measly 55 amps, then surely upgrade to something in the 85-100 amp range. there is a vendor on here(in his sig) that has upgraded alternators for our cars.

hope that helped you a little... good luck.

 

Hey badhabit90 how do you charge a cap , I have a cap for my 760W amp to power my two "10's and my lights keep dimming. I was never told that the cap could be charged, how can this be done?

Here are some pics so you can see what i'm talking about







And i'm waiting to install this amp once I get this issue resolved and my mid-range speakers are bought




P.S. Does anyone has a solution to prevent rattling in my trunk? I want something that can be removed and dynamat is $200 WTF!!!

Thanks In Advance

 

hydroliks..im no expert...but to be honest i dont even think u need a cap for what you have..and with it ur lights are still dimming?? thats not right i dont think...idk unless the 08's are alot different then my 03...im running two 12" infinity kappa perfect vq with a monoblock 800 rms alpine amp..also a 75x4 mtx for the components..my setup doesnt even need a cap...my lights dim at idle but im workin on that..the cap wont do much i dont think

 

What the heck is going on then is our alternator that sh!tty I want this fixed! I hate seeing the lights dimming when I stop at a light. What should I do? And J Money do you know how to charge a cap?

 

To charge a capacitor, you just cross the two terminals with a resistor...but it's been years since I actually used one that I don't remember any more. Caution, that resistor when crossed will be HOT!

A cap probably won't fix the dimming issue, it's just our line of alternators suck!

J Money - What MTX 4-ch amp do you have? I had a 6004, but the amperage draw was too much for the system with the sub amp too. It was like 50/60 the 4-ch alone...

 

^^ SLVR i have an older one its the mtx thunder 4244 i looked its rated at 60x4 watts but the actualy was 86 er sumthin like that when it was tested..its pushin 4 memphis 6 1/2 components

 

You don't need a resister to charge a cap.

First, you only charge a cap prior to the first installation. You apply a slight charge to it so when you wire the positive wire a burst of charge isn't pushed into a "dead" cap causing it to explode. Its rare, but it can happen. If you have already installed your cap and been running it, and nothing exploded, you are fine.

Second, to charge a cap, you ground it and use a test light (a little trick us certified installers do). Apply the alligator clip to the positive cable and touch the + prong on the cap with the test light tip. Hold it there for about 30-45 seconds. Now wire your positive wire to the cap. You are done.

As of current, there are no aftermarket alternators that I have seen. I suggest looking into the alternators for the Dodge Caliber or even the new Outlander. Theres may be larger or produce more amperage output.

 

Copied from a well-known cap. manufacturer :

Charging with a Resistor:
Many capacitors will need to be intialized with a 10 to 50 ohm resistor connected to the power main for usually 8 to 25 seconds depending on the size. After charging is completed, simply connect the power main VERY Carefully.

 

Sure, you can go to a store and buy a resistor (many caps come with one) but when you install them all the time and have a test light there, its easier and works just as well.

 

thanks for all the info guys, I really appreciate it