[attachmentid=17743]Well after finally getting the correct information I completed the installation of the Nakamichi CD-400 in my L6. I wanted to use the existing factory amp and speakers. I also wanted the in dash fader control to be operational. After allot of research and posting I finally got the correct method of installation for this set-up from a professional installer and it turned out to very easy.
As you know the factory wiring has only two speaker wires connected to the old head unit. These speaker wires are actually only front left and front right positives. They are simply right and left positive to the fader. The fader than sends four positives to the factory amp. So all you have to do is take the front left positive speaker wire from the Nakamichi and connect to the front fader wire of the car. Then simply do the same for the front left. Thatís it! No messing with the fader harness at all. What this does is simply feed with factory amp with 1/2 the wattage out to each channel since you are only using the positive of each speaker output. The ground is common to all, so just hook up the ground from the car to ground on the Nakamichi. I also took one of the remaining ground wires and connected it to the ground screw on the Nakamichi. All the power connections are very straight forward. The car wire out colors are as follows:
Speaker left positive= YW
Speaker right positive=BU
One thing to keep in mind is make sure you connect the wire marked remote on the Nakamichi WT/BU to the power antenna wire WT on the car. If you connect the power antenna wire from the Nakamichi to the power antenna wire on the care you will be able to listen to the radio but as soon as you stick a CD in and the power antenna retracts it shuts the amp off and you will get no audio from the unit in CD mode.
The new unit looks great installed and doesnít at all detract from the looks of the dash. This Nakamichi unit with the old factory amp sounds great!!!! Great bass response and good highs. I'm sure replacing and re-feeding the factory speakers and replacing the old amp would make for a better sounding installation but based on how nice mine sounds it couldnít be that big of a difference. I also doubt the extra time and cost would be worth it unless you are true audiophile. I'm just ecstatic to be able to finally enjoy some Tom Waits in my fine old car. Hope this post helps and thanks to all who took the time to make suggestions and recommendations to my earlier posts