SonoraMike

its not a nak, so it must be the premium then

ended up buying the $10 tech manual subscription, but for the purpose of understanding the radio/amp setup it was worthless. the schematics are incorrect - at least for my setup. so I ended up pulling the radio out and tried to bring the signal in via the cassette deck head. in hindsight I should have checked to make sure that the cassette unit was operative before starting because it never really seemed to work right. I was able to find the output wires off the head and connect the aux jack off of those wires but the tape button never kept the tape side active (even after tearing most all of the cassette mechanism out so that all the switches that I could find would be active) so going for an aux port off of the cassette head was a whiff for me. I did manage to find the speaker out wiring stenciled onto the PCB in the radio so I'm going to have another go at it with a relay setup, and I think that the scoshe wiring kit for the toyota (pn ta021 I think) might work - it came with 2 plugs and iirc they seemed to be shaped correctly. I sacrificed a tape deck to the mp3 gods, hopefully the next round will bring some better success

there are 4 plugs under the pioneer (non CD) head unit when you remove the center console bezel, plug on the left as you are looking at it is orange, then to the right of that is a green plug, then a 15 pin white plug to the right of that, and a grey plug on the right most side the white 15 pin plug carries stereo (the grey is climate control, not sure about green or orange) looking for pin outs on the white plug to try to pick out the audio wires to the amp in the trunk if I look at the face of the plug I have a 3 rows of 5 pins across. numbered left to right starting on the top row I have: 1 green/red stripe 2 brown 3 blue/yellow stripe 4-5 blank 6 white/red stripe 7 purple 8 pink 9-10 blank 11 white 12-13 - connector clip 14-15 blank assuming blue/yellow is power, and that brown is ground. heading out to read those out with the meter soon. appreciate any help I can get here, thanks in advance is it bad form to post this same info/question in the audio section?

have identified the plug that carries radio power and signal, wires are diff colored, will need to do some further investigating

the stock unit, this is all new to me. if there are multiple stock pioneer HU's then I'll look more closely an FM modulator is not hard wired, since if it was hardwired it wouldn't be an "FM" modulator. it broadcasts an FM signal that comes in thru your antenna. much different (poor) signal quality vs wiring the ipod/mp3 player (digital quality) directly to the amp as a line level input have the dash off now, tracing wires. should know something soon

needing to remove the stereo also, and ran into the issue with the shifter being in the way. the link in the prev post has been replaced with a ecommerce link. so dug into the internet wayback machine and came up with this link that shows the pics and instructions: http://web.archive.org/web/20041217132351/...xusSC300Str.htm

I think so, I'm working on it now - using the 4 relay plus switch that has been written up in here (somewhere, searching now) as the basis for the change edit: the link to the relay info is here the FM modulators still pipe in the digital audio via FM which kills a lot of the clarity, but they are a quick and easy install and work good will keep you posted as i make progress - I'm out in the driveway now looking at the wiring on the pioneer amp that I've pulled from under the carpet on the passenger side of the trunk found this post at another site too, uses a single 4 pole relay and a relay socket board: http://my.is/forums/f103/another-successfu...roadyxt-277880/ on the amp in the passenger side of the trunk the wiring is: <plug view looking at the face of the plug, pin 1 in the top left, going L -> R across the plug face> top row: 1 - red w/white stripe 2 - black w/ white stripe 3 - blank 4 - brown (a larger sized wire) 5 - pink w/blue stripe 6 - white 2nd row: 7 - grey 8 - blue w/yellow stripe 9 - no pin present, clip for plug retention into socket 10 - no pin present, clip for plug retention into socket 11 - red w/black stripe 12 - black next job is to pull head unit and see which plug on the back matches the colors. I'm guessing that the scosche kit has the info on the pinouts for the 4 channels noted, I'll see if my local walmart has one in stock should be a matter of 1) pulling HU and finding correct plug 2) determining which wire is which signal (LF+, LF-, etc), might need someone to dig this out via service manual since I can 't find a scosche kit # for the SC400 3) determine viable spot to install relay board behind the HU in the dash 4) find a decent power switch at the shack 5) find a spot to install the switch 6) install it

some new news on this, visited the previous owner tonight and he had run across a extra key that he had cut at some point. said that it opened the doors but wouldn't start the car - assuming that this is some sort of valet key. so i came home and tried it in all the locks and the tumblers/cylinders work great with this key, including the ignition -- the key enters the cylinder cleanly and moves thru all the positions but when in the start position it won't turn the starter over. I thought I'd read somewhere that holding the key with the transponder in it next to the ignition will allow the non transponder key to start the car, but no go. so the good news is that all the lock cylinders are ok, and a cleanly cut key will work well with them, now I just need to replace the master key

I'm a soon to be new owner of a 92 SC400, high mileage but incredible shape, everything works just fine but having key trouble. I'm hoping to hear about options from the more experienced owners on how to resolve this key problem described below. The search function on this site is tough to use for this problem since it doesn't like 3 letter word searches so I can't just search for "key" unfortunately. Google search on the site gave up some good info tho' I have one worn out master key with the remote button that is real tough to get all the way into the cylinder barrel on the ignition, it'll start into the cylinder, go about 1/2 way and then start to bind up and that last 1/8" is near impossible. I'm scared sh!!!ess that the key will get stuck in there or that the cylinder will end up trashed and stop working at the worst possible time forcing me in to having it hauled to the dealer for their special type of magic on my wallet when I can least afford it. The same key in the door locks exhibits the same trouble but not quite as bad. once the key is in and seated in the cylinder (either door or ignition) then the side to side turning movement is very smooth I've seen that cylinder barrels are available for other Lexus models, but didn't see anything specific about this with the SC4 I'm still kinda confused on the need for programming, while having the button on the key to open/close the door locks would be great I'd be able to live fine without it. But am I correct that it seems that the key needs to be programmed for the ECU to allow the motor to start? So how would you resolve this problem? I'm assuming that the key that I have is worn out, I don't think that the owner has the original key set with the little tag that shows the key code. Am I after the HYQ1512A key? I'm good with a wrench and a screwdriver so I'd like to do the replacement myself - but I'm unsure about how to approach the fix, what parts I should get and from where? The info in this post (http://www.lexusownersclub.co.uk/forum/index.php?showtopic=7960) about "Is200: Changing Your Ignition Lock Barrel, and save yourself some ££££££££££££!" is well within my mechanical capabilities but would it work on the SC? thanks in advance Mike