I have just tried unsuccessfully to install an aftermarket HU in my SC400. Mine came with the Nakamichi setup. I purchased one of those harnesses off Ebay which come with the RCA connections and plug into the factory "A" 15 pin plug. I hooked it all up and got nothing but hissing through my speakers. HU would not power up. I could never get it to turn on. I have relied on all the posts of hookups on SC's and apparently looking through everything there seems to be alot of doubt as to what does what.............I have yet to find a single solitary defined answer.

I NEED THE HELP OF PEOPLE WHOM HAVE ACTUALLY INSTALLED A HU in an SC400 with the NAKAMICHI setup. Please inform me as to what you did and what worked for you. I would really appreciate the help. Thanks!!

 

bypass the factory amp, get a print out of the wires behind the radio that you need, then run your speaker wires to the back passenger corner of the trunk to tap into the speaker wires.

the wire codes can be found on here as well in the SC section

 

I purchased a standard Toyota 87-UP Metra harness and compared it to the one I already have and the wiring does look different......looks alot more promising.....Hopefully this will fix the problem and get everything working correctly.
Anyone else have any insight?? Any and all help will be greatly appreciated!!!

 

any updates on this?

 

i am doing the same i would like all the info on this

 

easiest way is bypass the factory amp run new wires to the plug that is in the trunk and ur good

 

got pics cause i did my install and i heard nothing or seen nothing i felt like i just waisted time and i have the 87 merta harness

 

I NEED PICS IF any of u have SOME

 

what wires

 

Do you intend to bypass your factory amp also?

I replaced my Nak system in my SC last winter and the best thing to do was to cut into the factory wiring. You only need two wires. 12 volt continuous power, and power when the ignition is on. There are wiring diagrams that are posted for our cars have even the color code of the wires, but to be sure I used a voltage meter to verify. The only other wire you need is a ground and there are plenty of options to tap into an existing ground or create a new ground. If you are going to create a new ground make sure it is metal to metal contact....no painted surfaces.

I took my factory head unit to the local shops and there wasn't one Toyota harness that matched up the pin out for the NAK SC connector. There are guys here that have found them in the past, but in my experience the best route was to cut. And trust me...I did not want to cut.

 

so i decide i will go with the tappin into the wires but im havin trouble findin the power wire
turn on wire and do i need the illumination wire