Cap Not Working Right?

I recently installed a 1.25 Farad capacitor in my car to try and fix my dimming lights and give the amp the extra power it needs.  I have a Kicker 500.2 amp and I'm running two 500 Watt RMS Alpin 12" subs in a large dual chamber sealed enclosure.  If I understood the wiring correctly, I ground the cap and I run power from the battery to the positive lead and again from the positive lead to the amp.  I'm using 4 gauge wire all the way back.  The cap is lighting up and the built in digital volt meter reads just over 12 when the car is off and around 14 when the car is running.  When the stereo is running, the base hits can get the reading down to almost 11, but my lights are still dimming.  Shouldn't the light stay stable unless the cap has been completely discharged and reads 0 volts?

-Dan

Your cap is properly working it's just that you alternaor is not supplying enough current to keep your lights from dimming.

Hi Dant

With dimming lights a cap is not always the best answer.  A cap will only stiffen up the current to the amp not increase it. 

A cap will never completly drain as long as there is a power source attached. 

The over all problem is that your alternator is not strong enough to power all your equipment.  The alternator was designed only to power all you standard vehicle's electrical equipment in a heavy load situation.   You need to purchase a high performance alternator.  I would give you examples but i dont know what type of vehicle you have.   There are a few reasonably priced ones on e-bay.  Just make sure its the right one for your vehicle.

The other upgrade you should concider is a high output battery. For example Optima Battery creates an awsome battery.

Hope i was a help. 

Phill

Thanks Folks.  I have a 2000 Ford Taurus Sedan, if you know of any specific replacement altinator.  I've heard the term "Deep Discharge" battery being used when a higher performance battery is required... is this what the Optima battery is?

-Dan

As Phill_b explained to you a cap dose not generate current which is what you need. Allot of people have the misconception that the cap will solve all of their power needs when in fact it just adds to the problem. Since now your car has to supply power to the cap, stereo, and cars electrical system it puts more of a strain on the electrical system. Also if you don’t have the proper power being supplied to the amp then your amp will not perform as it’s designed to. As far as the high output alternator goes it’s the only solution. Your amp alone will draw about 78 amps at full volume. Now I'm not sure what your stock alternator puts out but I would call an auto parts store and find out. What ever it puts out add 80 amps (the draw of your amp) and get a high output that meets or exceeds the stock alternator +80 amps. But one thing to remember is you can never have enough power so if you only need 160 amps it won’t hurt to have a 200 amp alternator. Now when looking for alternators you should always l ask what the rating is at a hot operating temp. The alternator will put out more amps when cold but in a normal operating environment it will always be hot, so a hot rating is more accurate. When upgrading the alternator you will also want to upgrade all your power and ground cables between the battery, alternator and chassis. your battery cables are like pipes and you  alternator / battery is like a pool, you wont have as much water flow thru a 1 inch pipe as you will thru a 6 inch pipe draining a pool . So in order to move the power you need a larger cable,
 Below are some high output manufactures the prices will range from 250- 550 + I have not dealt first had with all of them, but they have all been used with good recommendations.
Dominick 615-287-7991, Michiana Rebuilders 1-800-627-4812,
 C.S.A 1-334-712-9955 or 1-334-791-6272, https://www.mechman.com/home.html
https://www.wranglernw.com
https://www.mralternator.com
https://www.alternatorparts.com

Yeah, agree that the altinator is the source of my problem.  Not quite ready to drop 200+ on a new altinator quite yet, so I guess I'll live with dimming lights for now.

Thanks for the advice all!

-Dan