Like most of you, I installed an aftermarket HU, and loved it. Way more power, and tons of features. After that, I upgraded the speakers, and wow, that made another huge difference. If you're going to do an aftermarket HU, definitely replace your speakers too (preferably with 3-ways).

After awhile, I did some research and learned that my HU was sharing a fuse with other electronics in the dash. I obviously wanted the HU on it'* own circuit, especially for security reasons (when it gets loud and sucks the juice). After looking at the wiring and kicking myself for being stupid, I came to a much overlooked conclusion. THE WIRE SUPPLYING POWER TO YOUR HEAD UNIT IS WAY TOO SMALL. No joke, I would guess that the wire was about 20 gauge, which is way too small to carry approximately 8 amps continuously (a 50Wx4 peak, 23Wx4 RMS reciever). Worse yet, that was a good 2 foot run to the fuse panel, plus another 2-3 feet from there, where it shares a larger wire (12-14 gauge) with other systems that are hogging power.

Anyhow, I installed a 3 foot run of 18 gauge, created a maxi-fuse under the hood for the radio specifically, and tried 'er out.

What can I say...the upgrade to a new HU sounded awesome. The upgrade to new speakers sounded awesome. And now, the upgraded wire sounded equally impressive. Lows became lower...contrast became greater between lows and highs. But most of all, it hits so very clean and crisp. In fact, I had considered installing subs to fix the bass, but was so impressed, I'm not gonna worry about that for a while. My rearview mirror even shakes impressively, and that'* without listening to distorted, clipped bass. By not distorted, I mean turning the volume 2-3 units (on a sony) below the point where you can barely notice distortion). Now, my system rivals those that have dedicated 4-channel amps attached to the interior speakers.

Lesson to be learned: The wire that carries the power to our HU is much too small to get the job done right, and upgrading 18-20 gauge to just 16 gauge makes a huge difference, and is also safer. Every install I do from this point on, in other people'* vehicles as well, I will upgrade the main 12v source wire as well as the ground, and put it on it'* own fuse. It'* such a cheap and easy process that there is no excuse not to do it.

I'd love to see someone here do this, and confirm my findings for the others. Or better yet, I'd love to hear from someone that has already done this. Happy wiring!

Okay, let me confirm this. You have an aftermarket head unit.. with aftermarket speakers, but the speakers are only hooked up to the preamp outputs on the aftermarket head unit, correct? And all you did was have the aftermarket head unit plugged into the factory wiring harness, using a converter from wal-mart [or equivilant], correct? And so, you removed the previous power line, comming from the fuse panel, and put on some heavier gage wire, just for the power to the head unit, nothing else, correct? I hope that whole thing made sense.. this is kind of confusing me.


-justin

Correct, for the most part. I just used an adapter harness....GM to sony. Everything is hooked up how it is spose to be, with nothing on the pre-amp outs, remote, or sony changer bus.

And yes, changing the power wires to heavier gauge wire makes a huge difference.

okay cool.. sounds like a project to do on my factory head unit.. how much did you spend on the whole thing, and what amperage maxifuse did you use?


-justin

It cost less than 10 bucks. The maxi I used was 20 amps.

okay, well if I find $10 in the street, i'll be sure to do that.. thanks dude, great suggestion!


-justin

I would also upgrade the ground wire as well.

So, you are talking about hooking up a new Constant or Ign wire? My headunit uses both to operate, if constant isnt there, the unit wont work. You think I should do both, or stick with whatever one you say? Main reason is I plan on putting in a eq with my headunit, and plan on piggy backing the power/neg leads and want to make sure it gets fed the right amount of power. Thanks!!

The only two wires you need to upgrade are the constant power and ground. The HU doesn't draw much juice from the accessory, or any other wires for that matter.

i have an alpine head it is specifically made to be connected directly to the battery, i till need to install an amp tho