For you guys who've installed amps in your trucks I have a question about running the power cable. Did you run it into the truck through the firewall or under the cab and in through the back of the cab? Seems like it might be easier to run it under the cab and just drill a hole in the back somewhere.(although I haven't taken a close look at it yet) This way it seems like I would have more room under the trim panels for RCA and speaker cables.

You can sneak a wire into the air vents on the back of the cab between the box. Just pull insulation back inside.

I haven't installed my amp yet, but I plan on doing it sometime this week. I have already started planning the wiring scheme. I personally would not run the power wire under the truck but that's just my opinion. If you look right above the master cylinder, right under the grounding wire for the hood, you'll see on the fire wall a big rubber grommet with a couple little wires(not sure what they are or where they go) going into the cab. I think that's where I'm going to go in with my power wire. I haven't had time to get in there and really see if it will work or not but I will, and I'll let you know.

Another option I found, from looking at the Brakesmart site is drilling into the firewall. Here's the link so you can see what I'm talkin' about.
http://www.brakesmart.net/manuals/bsm_gm_ins.pdf
Look at figure 4. Now, I'm not sure about this either so do at your own risk.

So there's a couple options for ya !

Also, I read on the Cruchfield site that you should run the power cable and remote turn on wire as far apart from the rca cables as possible so you don't get noise interference.
http://www.crutchfield.com/S-iPyaCbE97lu/tech/kb349.html
So I plan on running power wires down one side of the truck and rca down the other.

Thanks for the insight, I'll take a look around the truck when I get closer to installing all this stuff.

PalmvalleyGMC - why do you advise against running the wire under the truck? I was thinking I could hide it up in the frame rails or something.

Well, It would probably never happen but there's a chance the insulation on the wire could be chaffed or cut when your offroad or driving and something slings up under the truck and ground it's self out. I suppose you could use split flex tubing but I would think that would be more trouble than just running it on the inside of the truck. Again just my opinion.

I ran both of mine through the firewall. Then ran then underneath the molding along the door. Very clean install.

Ben

Ran under the cab through back air vents. Amp is under the back seat. I did it this way when I went to a bigger amp. With a smaller one I came thru the firewall. Wire got to big to do that way.

jcummins - how big of a wire are you using right now? 2awg? 1/0awg?

The one above the master cylinder won't work cause it just goes up into the void where the wipers are. But I did find one you can get into for sure, it's just below the master cylinder to the right and it comes out right above the connector panel. I think that's where I'll go in, just carefully cut a little slit in the rubber grommet and push the power wire through.

I ran mine behind the battery on the passenger side front quarter panel and cut a small hole in the rubber protector for the wires going into the door. Then just ran it down along the floor.

waskier - running 1 gauge, also after market 235amp alternator. When I keyed the amp it was obvious I was pulling down the alternator, not now though.

haha, yeah it sounds like you've got your power issues taken care of. Why didn't you just get a second alt though? Was the aftermarket alternator cheaper?

I thought about another alt....but I think a single was cheaper, and certainly much easier to install. BTW you don't need 1 gauge with most amps....you need to size the wire to the amp draw.

1 gauge thru the fire wall down the drive side along with the remote wire, rcas up the passenger side.

I've got two MTX amps

One is the 2300x which makes 750-800watts bridged
The other is a 4202 which produces around 200 watts
I'm thinking I might want to run a 4 channell setup in this truck though so I may be adding another 2Ch amp in the future.
I also may install a power inverter around 1000watts

with all this in mind I'm thinking of either running dual 4awg power leads to my distribution block or a single 2awg cable.

Do you think I need a 1/0awg? the price difference isn't too bad between the 2 and 1/0awg wires. Although I'll have to get a different distribution block for it.

welding shop was out of 2 gauge, and price difference on 1 gauge was nil. I used 1 gauge not 1/0, that is bigger yet. This setup has worked the way I wanted. I used welding lugs to the jumper point under the hood, and a quick connect on the amp end, with 8 gauge jumper solder directly in the lugs on the quick connect. This is so I can add a driver amp....which I don't have yet. I'd add up the amp draw, and I would not undersize. I have ran into other guys who did so and you can tell it. Mine gets out pretty decent.

Thanks for the help.

I didn't know there was a 1 gauge besides 1/0 i thought it went 4, 2, 1/0, 2/0... learn something new everyday...

I ran both of mine through the firewall. Then ran then underneath the molding along the door. Very clean install.

BenMe too.

I thought about another alt....but I think a single was cheaper, and certainly much easier to install. BTW you don't need 1 gauge with most amps....you need to size the wire to the amp draw.It might have been cheaper but a dual 105 alternator setup will put out more voltage at an idle or low rpm than one big alternator. You have to spin the one big one at a higher rpm to get the same gains.

A good place to go through the firewall is here. Nothing behind it and comes out above the gas pedal. Wires are easy to hide in the center consule.
http://pic13.picturetrail.com/VOL487/437876/777914/24920271.jpg
One of my wires is black but is a +. Its the only color I had that was long enough.
http://pic13.picturetrail.com/VOL487/437876/777914/24920201.jpg
Pic above the gas pedal.
http://pic13.picturetrail.com/VOL487/437876/777914/24920054.jpg

I've got no center console to hide the wires under...

Run them under the carpet........done......

nice thing about the Diesel trucks is that you dont have to be too worried about the RCA's getting too close to the power wire, or even being run down the same side of the truck as them, in a gas motor it is possible to get the ingition system to interfere with the signal from the power wire to the RCA's. But with the diesel there is no sparkplug/ignition interference to mess them up!! just an Idea that it may be nicer to only have to pull one side of the interior apart when installing the stereo. JMHO! -Jeff

I ran the a wire off the pass side battery post(and put a fuse right there) and down along the fram rail and drilled a hole in the floor in one of the glue in factory plug deals and used a plastic gromet thingy(any good stereo shop will have one) and have my amp under tha pass seat(reg cab remeber) I used wire thats at least as big as your pinky, cant remember the gauge its called but its FAT.

Lift the door sill plates and run your wires under there.

Sounds like power cables have been run everywhere you can think of in these trucks!

It you run the power wire next to the RCA cable you will get interference, well at least I did and had to move the RCA cable.

It you run the power wire next to the RCA cable you will get interference, well at least I did and had to move the RCA cable.Always run the RCA down one side, and the power down the other. The sills are the easiest way to run cables....there are channels built in.

Well I was under the impression that the whine was caused by the alternator. Maybe wsucowboy has just had good luck with his system.

I have had pretty good luck, although I am using shileded RCA's and they are only about 3 feet long, because of my DVD player all the RCA's run from the brain under the middle rear seat on the hump to the Sub amp under the passengers rear seat and the Mid/High amp under the drivers side rear seat. I totally forgot about that when I posted before, I was thinking about the way it is run in my dodge. Oops -Jeff

power is on the drivers side, 8 guage on a 400w amp running 2 8" subs. rca and remote wire on the pass. side. only get interference on the am stations, so i installed a switch on the remote wire, shuts the amp off and no more interference!!! besides the switch used to be used for an arming switch for a friends no2 setup, makes for good conversation-----ooohhhhh so you have nos too.