Here you can see the final upgrade, which is engine block to frame ground. There are many bolts you can use….just pick one and make sure the connection is clean. You can see this one in the lower left of the first picture. It was a tight fit to undo this bolt and connect the ring terminal, but I did that and then connected it to the frame ground location, as seen in the second pic.
Now reconnect your negative terminal and test everything. Here’s a final look at everything during testing (right before I finalized their locations and zip-tied them in place). You can see that I still used too much wire for some locations, but it’s better to have a little more than run short.
Before/after videos using Gryphon's voltage display
In both videos I did two things: rolled all four windows down at the same time and cranked the system up. In the first video it took me a minute to get the song playing (sorry) but I cranked it up about as loud as I'll ever listen to it. In the second video I cranked it way past what I would normally listen to and then dropped it back down to the loudest I'd ever listen to it. Sorry for the crappy sound but my D90 doesn't pick up bass well at all. Made it sound really choppy.
Note that in the first video, the voltage idles around 13.6. It drops to a minimum of 12.8 while rolling the windows down and back up. While fluctuating with the music it drops to a minimum of 12.8 as well.
Now in the second video note that the voltage idles around 14.1. It drops to a minimum of 13.5 while rolling the windows down and back up. While fluctuating with the music past my regular listening levels it drops to a minimum of 13.4. When I lower it back to regular listening levels it doesn't fluctuate at all except on the heaviest bass notes. All in all I consider that a success.
• Try to keep wires away from heat sources inside the engine
• Leave some slack in the new wires for the movements inside the engine bay
• Don’t bother disconnecting stock wiring if you don't want to—current takes the path of least resistance so it won’t hurt anything
• If you still have issues with voltage drops/dimming headlights/etc the next steps for you are to upgrade your battery and alternator (I'm saving up for this)
• This isn’t a difficult task to accomplish as long as you understand what you’re doing to your electrical system. After prep time (including gathering material, cutting wire, attaching ring terminals, etc) it should take an hour tops to install everything.
Hopefully this answers any questions you guys have about this. If not and you still have questions, please ask. Many of us here are willing to help you.