for a general rule of thumb you can pull the speaker on the door and the radio (both very easy on these trucks and look for wires of equal size and color in both locations if your system is not an amplified system it will have 8 wires of the same size and most likely some type of pattern (ie brown stripe or for all negative leads or one color for all negatives with a different color stripe) and generally each pair of speaker wires will be twisted together (this usually starts a few inches up the harness from the radio so you may need to cut away some loom tape to expose more of the wires)
if your system does have an amp it is most likely high in the passenger kick panel, mounted on the wall.

as for AK Rovers statement yes you will need to run speaker wire as you cant rewire behind the radio however I run my speaker wires from the new head unit to the factory amp and get the factory speaker wires there, just be sure to unplug the harness from the stock amp. This makes the install cleaner, easier, and cheaper (cause you only need about 3 or 4 feet of each speaker wire)

 

Hadn't thought of that, thanks. I guess to verify one could use an ohmmeter or continuity tester once the wires are out, right?

 

yep or if you are pretty sure you have found the speaker wires you could use a small AA battery and some wire to "pop" the speakers from behind the radio, but I wouldnt suggest that unless you have a pretty good idea of what you are doing.

 

I like your idea of running the wires back to the factory amp and connecting to the speaker wires there. I'm not really impressed with my current setup although it works well. What did you do for the factory subwoofer amp in the rear door?

 

left it there disconnected and built a custom fiberglass sub box (12") to go where the passenger side jump seat was. I am sure I could have used the schematics for the factory sub amp wiring and a splitter on my sub channel to incorporate the factory sub and amp, but mine didn't really sound too good when I bought it so I just put in something more to my liking (much louder,cleaner and nicer looking!!!)

 

I can't afford nor do I have the skills to build a custom enclosure so I think I'll stick with my stock subs now. Do you know if the factory sub amp uses speaker lever inputs?

 

no it uses a low level signal from the main stock amp. It appears from looking at the schematics that there is a 6 pin plug at the sub amp with the following wires in it: )) PIN 1.) (I believe it is just a bare wire) shielded low level cables common ground (if wiring up a pair of RCA cables as inputs this would be the ground wire for each RCA cable), )) PIN 2.) red wire shielded (I'm guessing right channel) rca positive wire.)) PIN 3.) black other positive RCA shielded cable.)) PIN 4.) Light green/orange, power wire to amplifier. )) PIN 5.) purple/yellow wire this appears to go from the back of the head unit to each amp, so I would assume it to be a remote turn on wire(should just need 12 volts, but I am not responsible if someone fry's there amp if I am wrong) . And last pin 6.) black and it is a ground for the amp.

these low level signal wires (pins 1,2, and 3) also connect to another plug at the tailight bulb access panel where the wires run into the rear door however the schematics show they are different pin locations and one of the 2 connectors appears to use different wire colors. but if I was going to wire into this system I would do it as close to the head unit as possible like at the main stock amp and just grab the remote turn on wire at the back of the radio.

 

I guess since I would do it this way I will add this the main stock amp has a white 18 pin harness plugged into it. the low level wires going to the sub amp are pin 10.) this should be the ground wire to connect to each RCA as the ground (it will either be black or bare), pin 13.) which is the red wire (should be positive right) and pin 12.) black wire should be positive wire for left channel. pins 12 and 13 are under the release tab in the middle of the plug.

 

Silence?????? This vehicle is tooo perfect!!! From the inside of (for less clean up) the vehicle take a rock about the size of a baseball and throw it through the rear passenger side window to allow some good ol environment in. Hell you might even get some road noise all up in there. After a coupla weeks you'll realize you don't even need a radio!!!

Cheers

Robert

 

How do you remove the stock unit in an 04 Disco II HSE. Its the Nav/CD player style head unit. Thanks.