Thread: Big 3 Electrical upgrade

Hey folks,

I've recently installed an amplifier and subwoofer combo. Amplifier is the alpine mrp-m500 powering an mb quart rwe 304 DVC wired in parallel so it's pulling the max wattage. Under higher volume, my lights dim pretty badly with the bass hits. So, first step I'm taking is the big 3 upgrade.

I was just wondering if anyone had some pics to share of their Big 3 upgrade, or knew a link of a Big 3 specific to an 04+ grand prix with the base 3.8l.

Also, where is the engine ground to chassis ground on these?

Any tips or other advice on this is helpful. I know it's pretty straight forward, alternator + to battery +, battery - to chassis, and engine ground to chassis ground. I've never done it before and would like to see some additional info/pictures on a similar vehicle so I can go in it with more confidence.

I've already purchased 2AWG wiring to do this with. I've got 4ft of power and 6ft of ground to work with. Also, I plan on bypassing the stock wiring so I was wondering what size in-line fuse would be recommended. Alternator is 125A so I was thinking 150, or 160A for the fuse?

Thanks in advance.

Redo your grounds.

Proper "Big 3" for our cars is really a "big 5"

Just redo your grounds and connections.

Not trying to revive a dead thread, but what are the big 5 in 04+?

I found
battery+ to alternator+
battery- to chassis
battery+ to fusebox
battery- to engine (I think)

I can't find the engine to chassis at all, and I'm not even completely sure that the battery+ to fusebox even counts...

Alternator to fuse box.

Originally Posted by 1LoudGrandPrix

1st off its all FAIL
500W amp @2ohm your wired at 2ohm this is good
what are your settings on your amp:
Gain:
Bass EQ:
Low Pass Filter:
?
that info will solve your problem

Gain = 75%
Bass boost on amp (50hz) is +5 out of 12
Graphic equalizer, 80hz +4, 100hz +4
Bass booster on the deck is as low as it goes
No low pass filter is set

DIY on how not to be a huge jerk like 1LoudGrandPrix - aka The Big 3, everything you wanted to know + DIY (now with more alternator to underhood fusebox action)

all that gain is bad.

turn the bass boost off, and the EQ.

Originally Posted by matt5112

all that gain is bad.

turn the bass boost off, and the EQ.

Wouldn't this only result in my having to turn the volume up higher to get the same result, and inevitably, the same dimming problem?

I like the way my stereo sounds now as is. I can keep the volume low and still feel the bass, and if I wanna jam I can do that too. I listen to music mostly at a normal level, but I do admit I get a wild hair every now and then.

Although I have contemplated turning the gain down on the amplifier a bit. Somwhere between 50 and 75% probably. This is a 500Wrms Sub, and a 500Wrms amp.

I will experiment more with my bass boost and EQ adjustments though and see if I may be able to find a compromise in the works somewhere. thanks for the advice

Your gains should be adjusted properly as well.

If that doesnt result in enough "boom", you need a better setup seeing as something is missing.

Originally Posted by matt5112

Your gains should be adjusted properly as well.

If that doesnt result in enough "boom", you need a better setup seeing as something is missing.

seeing as the gain is already 3/4 of the way up, there isn't much more room i could go. i guess i could knock of the eq and bass boost while increasing gain to near 100%?

If I did so would this help minimize my dimming problem?

battery+ to alternator+
battery- to chassis
battery+ to fusebox
engine to chassis

What is the final one to make it five? jmoore and that link said alternator to fusebox, but 1Loud you said no.

I just want to make sure I get everything right the first time so I don't have to go back again when I finally find someone who makes a god damn HO alternator for a 2005.

Extra info: I'm running 900 watts to two original (and I mean original) L7's (they're surprisingly accurate until you crank it, then classic Kicker poo) with a 5 farad cap (I don't care if I don't need it, I get too many mixed responses). At max volume I get slight dimming, and as weird as it sounds, my transmission slips... not sure why, but I'm completely sure after a few tests that low voltage is the cause. So I'm hoping the Big 3 (Big 5) will help.

I'll try my best to get to the tranny's ground, I bet it'll be a *****... I'm getting it looked at this monday either way too, better to check than let it go and have it get worse right?

So as for the Big three, I guess I can leave out the fusebox, but what about that 5th wire? I'm still unsure as to what that could be.

And when I max my volume on my HU (I keep it safe at 30 out of 35) I'm pretty sure my amp isn't even putting out all 900 watts because I just adjusted my gains until my lights started dimming, and no distortion (at least none in addition to the distortion all square woofers seem to have).

I'd also like to get rid of the cap, but it really helped reduce my headlight dimming when I put it in, whether it was the cap or the extra ground. So maybe if rewiring helps as much as I hope it does.

You're supposed to set it with an oscilloscope but no one owns one....