Lights are still dimming with a 2.5 farad cap!

**AllShowNoGo** · 07-22-2008, 11:18 PM

I have a Pioneer GM-X802 class A amplifier. 300wrms, two 20 amp fuses.

When I installed it, I had a .5 farad capacitor and the lights dimmed when I pushed the amp. I picked up a 2.5 farad cap today and the lights are still dimming. Is this an issue of a capacitor can only help so much or is this class A amp drawing way more than I'd expect?

Thanks in advance!

**Woofnstuff** · 07-23-2008, 12:31 AM

which lights are dimming?

and i doubt a cap will help at all..
if its your headlights you are talking about sounds like you need a bigger alternator or a smaller amp.

what is the amp powering btw.. sub? mids?
if its a sub i would have though a class A amp would be a bit overkill for the job, and not the best choice of amp

**scott_fx** · 07-23-2008, 12:42 AM

there is no way that the pioneer is a class a ;-)

what kind of wiring do you have? (gauge) and how are your ground points? did you upgrade the big 3?

**AllShowNoGo** · 07-23-2008, 03:09 AM

I got a steal on this amp. $20 on craigslist! Its a GM-X802. If you search ebay for completed items you can find some pics of it. It says Class A right on the front of it.

I am using 8-guage wiring all around. The ground point is the end of a factory bolt that i put a wingnut on. I crimped an "eyelete" on the end of the wire and put it on the bolt. Due to the fact that this amp's connectors doesnt like smaller wires, both the power wires and the wires from the cap are connected to it. so basically it looks like this (its too late to bust out the digi camera):

power source====amp====cap

And yes, this poor amplifier is pushing my dear old 12". From a power standpoint, I realize a class A amplifier is the worst choice but i'm happy with the amount of power, it sounds good, and hell it was only $20

The guage cluster lights are dimming and the headlights are ever so slightly as well. You have to pay attention to notice the headlights.

While typing this up, I realized that I did make a "mistake" in the +12 power line... Its connected to the factory line since the battery is buried in the engine bay. GM used either 6 or 8 awg wiring. I doubt that I put an additional ground wire on the battery as well. It looks like I have a 105 amp alternator in this puppy.

**DarquePervert** · 07-23-2008, 07:02 AM

Where you grounded to the chassis, did you strip the area down to bare metal?

And where would GM use 6 or 8awg, other than a line from the battery to fuse box or starter?

What "factory line" did you tap into?

**_Dejan_** · 07-23-2008, 07:38 AM

You need better battery. Capacitor without good battery will not do anything good...
Try:
-Add wire from battery - conntact(ground) to ground in car.
-With multimeter mesaure how V(voltage) you get on battery when car is off and how when on.
-With multimeter mesaure how V(voltage) you get on amplifier when car is off and how when on.

Im fix my problem with new battery(70Ah and 2500A) and aditional ground cable(AWG 0) from battery ground terminal to car ground...

**AllShowNoGo** · 07-24-2008, 12:28 AM

DP - I will have to verify if the ground in my trunk is stripped to bare metal or not. I know I was in a little bit of a rush to get it all installed to begin with. The "factory line" I was talking about goes from the battery to a bolt (often used for jumping a car, also where my power to the amps/carputer is attached) to the fuse box.

Dejan - Good call on seeing how much of a voltage drop I have. I'll try wiring it up correctly when I get a chance

BTW, Here's a link to what the amp looks like.

**malcs** · 08-02-2008, 10:28 PM

I had this problem in my car for ages, albeit with a much more powerful setup (2000WRMS going to the subs alone!)

Fixed by putting in an optima yellow-top battery on a split-charge into the system. As I have now learned and have been told many times by people in the industry, capacitors are a waste of money in most circumstances!

**Bugbyte** · 08-02-2008, 11:09 PM

A capacitor is basically a way to supply excess power over a very short period of time. Once drained, it must be refilled. This has to take place very quickly, like between beats.

If your alternator cannot supply the power, it comes from the battery. Therefore, a better battery will help or a better alternator will help but a bigger capacitor usually doesn't solve the problem.

**Woofnstuff** · 08-03-2008, 05:20 AM

and if the battery is too big then you may get the next problem of it not charging up properly too.

just checking you did run a new positive power wire from the battery terminal to your amp?