91 LS400, amp & sub install

I tried a search but nothing turned out. I've got 91 LS400. My factoryPioneer amp (the one in the trunk is dead; blown) I'm wanting to install an aftermarket amp and sub to the factory system. I'm only adding one d-class amp, to a single sub. Retaining all factory stock speakers and h/u, replacing sub only.

I understand I need to run a new power wire, and ground wire, but what do I do about connecting an LOC and for the remote turn-on. The sub is the only speaker on the rear deck -- I can't use it for an LOC because the factory amp is blown. I'm wondering if anyone knew what wires to splice for an LOC, from the stock harness(in the trunk) that went into the stock amp.

The amp in the trunk only powers the stock sub, I know this because I unplugged the amp and all other six speakers played fine.

 Does anyone know what each colored-wire does?

Replace the HU. That will save you the headache of wiring and then disapointment when you get the ground loop. Those cars have literally miles of wiring in them. When I did my roomates amp install I ran the power wire UNDER the car. Trust me, that is the easiest way. The padding under the carpet is like THREE inches thick, remember those are some of the quietest cars in the world. As far as woofers go, get some loud ones because that trunk SEALS. I thought the woofers were turning off when I shut the trunk lid. Good luck. Try looking up.... umm.....lexls4oo......or .... ahhh...... lexls.org. That site is sic.

If you pull the head unit & check the wiring, you may see (I'm not sure) a piggyback setup where the wires that route to the OEM sub amp are connected to the stock speaker leads.  Then find those wires on the amp harness.  You'll have to do some testing.  First things first tho - find the power lead to that amp & isolate it to avoid any problems later on when you start cutting.

Hey Denm Can I hit some corners in that when your done?