So, I finished my audio build, my bass hits and I love it. My headlights dim and I don't love it so I'm doing the big 3. So I'm going to assume the Big 3 is
Alternator + to Battery +
Battery - to Chassis -
Engine - to Chassis -

Correct?

Onward, where is the Engine - at? Is it the one that runs off the Starter - or what? I found the Chassis - in the front passenger strut mount and another Ground wire from the Battery to the Firewall but I'm confused as to what I'm missing. Any info would be helpful!

 

Your stock grounds should be fine. I suspect you need a 220 amp alternator to handle the power draw that your stereo system is placing on the battery.

I'd go with a better battery and the 220 amp alternator. From this site: This Beefy Alternator is what you need for high amp stereo systems or for extra reserve power when you need it:

http://www.dbelectrical.com/p-9821-a...-06-07-08.aspx

 

I'm holding off on alternator as it's not a beefy build I'm barely pushing 1000 watts.

 

Then why are your headlights dimming ?

 

You could always wire in a capacitor for your sound system. It would be cheaper than that alternator. Also, I think the yellow wire is what you're looking for in the images on this thread:
https://www.f150forum.com/f75/how-bi...-46822/index3/

 

Definitely do the big 3 before anything else. As that is the cheapest and it can always help. Years ago I was a part of an audio forum and big 3 is highly suggested whenever upgrading audio and adding amps. If you aren't running anything too crazy the stock alternator should do fine.

 

This. I added a capacitor to my audio system on my Grand Cherokee, because the headlights would dim. Took care of my problem and it never came back up. I was pushing 1000 watts as well. 600 to the subs, and 400 to everything else. I ran 2 amps in my system.