Back in 2017 I installed a new stereo, speakers, sub-woofer and GPS into the rig. I added a Kenwood DNX773S head unit, a set of Polk DB522 5.25" speakers front and rear, along with a Bazooka 6.5" sub in the console. I've always been fairly happy with the install, and it has served me well. But, the head unit only puts out 22 watts to the 100 watt speakers, so I've always thought I was leaving something on the table.
So fast forward to a couple of weeks ago. Itching for a little project I reached out to a few audio guru buddies of mine and asked about possibly adding an amp to boost the power and clarity a bit.
The result of those discussions was me purchasing a Soundstream Picasso Nano Amplifier. It's a 5-channel pushing 60 watts to each main speaker and 200 watts to the sub. After some delivery delays due to weather here in Nashville, it showed up on my doorstep yesterday.
So now that I have a little project, time to start picking up some pieces and get a plan together for the install.
This morning I spent some time thinking about the best way to mount the amplifier up under the dash. My idea is to mount it up under the dash right beneath the steering column. So I pulled out my CAD skills and mocked up a mount that will be held in place by the two bolts which hold the back of the steering column. Here is my thought:
I'll make it out of 3/16" steel, and spend some time with a few hole saws to hog out a good bit of the plate to allow for cooling, while keeping it rigid enough since the amp is heavy. Then I think instead of using blue painter's tape, I'll weld the two tabs to the mount.
You may remember that a few months ago I ordered a big metal cutting band saw for the shop which would be perfect for this project. I just got a note that it won't ship now until close to the end of the month. Dammit! I guess I'll be bustin' out the old plasma.
Yesterday I built the mount for the new amplifier. Using the pattern I made earlier in the week, I cut out the main piece. To much of a pain to pull out the plasma to make two short cuts, so I used my trusty old circular saw / abrasive blade trick. Unlike the plasma, it makes a very clean cut that requires zero cleanup.
Then I cut and drilled the two tabs out of 1/4" bar, and beveled the lower edge for welding.
I did have to make a change from the pattern. I originally had the tabs centered on the plate, but there was not enough room to slide it on to the steering column bolts with the amp attached (that's why we tack, right?). So I cut the original tacks and offset the tabs.
Today I tackled the power side of the wiring for the amplifier. Since I like to keep my wiring organized and looking as stock as I can, and (mostly) because I just like doing things the hard way, I wanted to add the required 40amp circuit to the PDC.
Since it is pretty tight in there, to get to it I have to pull the battery and the battery tray.
Once that is out of the way I can pull the PDC out of the bracket, take it apart, and gain access to the underbelly.
Years ago I picked up a fully dressed PDC from Davey's Jeeps to provide me with the necessary connectors when I do a project like this. I found it easier doing it this way as opposed to sourcing the connectors new. So, I cracked that one open too.
I pulled this connector out of the donor - this connector came from the 50 amp IOD circuit.
I've never understood the wiring selections in cars. On this 50 amp circuit, I think the wire here is 12 gauge. Everything I've read on the amplifier, and electrical load in general, is that to support a 40 amp load under about 25 feet requires an 8 gauge copper wire. Much larger than the wire that Jeep used for this 50 amp circuit.
So I soldered the gigantic 8 gauge wire to the connector and covered it with heat shrink.
Since I still have a few open circuits on the bus with the larger fuses, it was just a matter of snaking the new connector through the other wires and stabbing it in place.
Then I tied everything back down and reassembled the PDC.
I have a large grommet on the passenger side where the cables for the welder pass through the firewall. That was an easy place to pull the wire and keep it waterproof. It was then an easy task to route it to the driver's side.
The amplifier documentation made a big deal of establishing a good ground. So the first thing I did was pull out my big crimper and add an eye to the 8 gauge ground wire. Here it is after some shrink wrap.
I took advantage of an existing 1/4" hole just above the steering column mount, and after grinding off the paint I added a 1/4" through bolt to attach the ground wire.
Next up - the wiring to the head unit. But now the nasty part is out of the way.
Yesterday I started into the rest of the wiring for the amplifier. First, pull the bezel and yank out the stereo to get access to the wiring harness.
I spent a bunch of time trying to decide whether or not to run new wiring to the main speakers. Running new wires and leaving the factory harness intact would have allowed me to more easily go back to stock if I ever needed to do so.
Ultimately, I decided not to because it would have been a royal pain to do the rear. My cage is fully padded and covered, and to pull new wire back there would have meant pulling all the covers, padding, and about 6 miles of black tape - and then putting it all back. @skrelnik's advice was that that stock wiring would work fine, so, I took the easy way out. Thanks dude.
I pulled out the FSM, identified the eight wires for the main speakers, and cut into the harness. I needed to extend those wires from behind the head unit over to the location of the amp. I solder spliced and heat shrank some 18 gauge speaker wire, which did the trick. After labeling those wires, I heat shrink'd the cut wires coming out of the connector.
That done, I added the RCA cables I needed for the pre-amp connection to the amp, and labeled those as well.
After routing all the new wires back to the amp location, I stuffed it all back in place.
Notice I have not yet put the bezel back in place - I'm not quite that confident in my wring abilities....