Big 3 done and still have dimming lights

[iamdub]

Really, it's one of those things that you probably need both. If the battery is a few years old, chances are that it's not nearly as strong as it used to be, especially if it's more of a budget brand battery. If the battery is weak and dropping voltage when loaded, the PCM is going to make the alternator pick up the slack. Over time, this extra work can take a toll on the alternator and it too starts to get weak. The weaker alternator can't pick up the weak battery's slack any more so the battery feels the strain more and loses even more of it's capacity. It's another downward spiral common in the electrical world. I'm betting you at least need a new battery and you definitely need to have your alternator tested by a specialty shop (and not by the gimmicky toy at Autozone by the most-likely-unqualified operator).

 

[ISU-152]

Yes I know the connections are clean, tight, and corrosion free. Checked all that when I had issues of the truck randomly not starting a few months back (ended up being security related)

I'd have to check white pages for an alternator or electric motor shop. I don't know of any off the top of my head. Although I never had to look for one yet.

I'm unsure of age of battery. Had the truck 4 years now. And it was in it when I got it.

So change the battery. It might show the volts but can't put out the amps

 

[ISU-152]

I've run a Sony 4 channel 1000w amp and a Kenwood 2 channel 800w amp with no capacitors, off a 3.1 motor/battery/alternator.