If I replace factory stereo with an aftermarket one will It still run the 2 6.5 subs in back with out changing anything

 

It will as long as you get the right harness. There is a special harness that plugs in the RCA jacks of your aftermarket stereo, and then plugs into the Disco's radio harness. You will still need to wire however for power, and the dimmer if desired. And if you want to add stereo controls.

If you do not get a the RCA harness, you will have to run speaker wire from the head unit to the where the factory amplifier is under the driver's seat. If done this way, you will also lose the rear subwoofers, and the two tweaters in the rear doors. Not a huge deal, but if you want all speakers producing sound, you must use the RCA harness that connects the head unit to the factory amplifier.

 

U wouldn't happened to have the link to right harness u are talking about

 

Apparently there is interference when using this harness. I remember reading somewhere about a little black box that can plug in and eliminate interference, but I don't recall exactly where at the moment.

For steering wheel controls:

I have this in my truck and it works like charm. Very easy to hook up.

What I did was just run speaker wire from the head unit to the factory amplifier. Cut the speaker wire off the amplifier, and wire the speakers directly to the head unit. Granted I lost the rear subwoofers, and the two tweaters in the rear doors, but I added a 10' slim sub in the back. It sounds great, so I don't mind. But not everyone's cup of tea especially if you are trying to keep all the speakers working.

 

Ah, here it is... Like I said, I can't really attest to the QUALITY of this route, but I know this is how you do it if you want set up like you originally posted.

Interference Isolator

 

Sweet thx bud

 

I have a stereo question as well. I replaced my stock alpine cassette deck with a cd stereo. I used the Metra 70-1786 Radio Wiring Harness everything is connected correctly, the stereo powers up but there is no sound?

 

you need to make sure you connect the blue (possibly blue and white) amplifier power wire.

 

Keep in mind that the Land Rover head unit interfaces with 2 factory amps, (one under the driver or passenger seat, one in the back door for subs,) and a CD changer. Plus you have two antennae with oddball connectors. Makes it interesting when changing out the factory stereo.

 

D2's have 1, D1's have 2. Rover has to keep things interesting. If your subs aren't working, then you may have your head unit set up incorrectly. If your audio setup in the head unit is for a subwoofer, then your low frequencies will be directed to the subwoofer outputs. Without any low frequencies going into yoour amp, there won't be anything to send to the subwoofers. Check to see if that is happening. Check these links for some info on the factory audio wiring. I don't know what year your vehicle is so I attached links for all years: Crutchfield Knowledge Base.
Crutchfield Knowledge Base