KahnBB6

iTrader: (5)

I understand. I'm aware it's been greatly surpassed by today's standards. For me I'm happy as long as it works as is. Whether I can keep it in there and use other nearby electronics is another story, so it may not stay for much longer despite my preference.

I beg to differ about SC's not approaching classic status though, especially if you add a bunch of hardware from the non-US versions or MKIV Supra to bring the driving experience in line with the looks. I do feel Toyota (and Nissan) in the 90's gutted these things for the U.S. market they were initially designed for. But that trend is still going on today with plenty of new models.

Anyway, thank you for your help with this, Raine! The possible noise on the shared +12V Constant and/or +12V Switched connections in addition to the ground location are the last things I will look into changing. If that doesn't work... then the OEM HU's days are numbered.

Begs the question though: would recent aftermarket HU's also get even some electrical interference noise from sharing the same two types of +12V connections through the factory stereo harness with another electronic device like an LXCC or... anything similar? Obviously the ground connection is always the first thing to check.

raine

iTrader: (7)

Classic by model year, sure. But "classic" in the true sense, not the SC. Maybe the Soarer (which had the right engine)... but here in U.S. the SC was just an overpriced Toyota that filled in a small gap created when the Lexus brand launched and it needed a 2-door offering ASAP. If it weren't for the whole "drift era" in the early 2000's there wouldn't have been this resurgence of interest in the SC. If you want a true classic late 90's Japanese 2-door, the SC is nothing compared to the Supra. You don't have to "add a bunch of hardware" to a Supra to make it something it isn't.

Don't get me wrong here - when I had my SC I loved it, but I had to do/add/mod/change a lot of it to get to that point (my build thread shows just how much LOL). For me, true classics are exceptional and unforgettable straight out the door

no prob, sir

Sure, they can - aftermarket or not - because you're still sharing a 12V+. If anything, I would leave the factory stereo power wire (12v+) to power the head unit only, and nothing else. If you have no choice but to splice to get power to another electronic device, at least splice into a harness that has nothing to do with audio components (i.e. cigarette lighter harness). By doing it this way, you at least keep the audio isolated from everything else, as intended. If there's electrical noise generrated elsewhere, at least you won't hear it through the speakers.

That scenario I described with the amp draw is a very common problem, usually happens when people install car audio and try to use one amp cable to power everything by splicing everything along the amp line. Like I said before - the issue is caused by the amp draw of one device being higher than the maximum amp draw that the other device(s) are capable of seeing. BTW don't confuse this with bad ground - having a bad ground can also cause noise but not in the same way. A simple way to kind of describe the difference is:

Shared amp draw = like saying, there's too much trying to go in
Bad ground = like saying there's not enough space to get out

Does that make sense?

KahnBB6

iTrader: (5)

Yes! That's a great analogy.

I am going to go back to the harness I made and separate out the +12V Switched signal to draw from the cigarette accessory splitter harness that's already done in the car.

However I also should do the same with drawing my +12V Battery/Constant signal from somewhere else, correct? Do you know of another good location for that?

raine

iTrader: (7)

It depends on what the other 12v+ constant is for. If it's just for memory purposes (i.e. radio settings, accessory memory) then generally it's a very low amp draw. Usually with head units the 12v+ switched is the main power supply. Whatyou would need to find out is how the LXCC thing is configured - I would guess that either it:

A. Uses 12v+ constant into an internal main power relay activated by a 12v+ switched (so high amp draw would be through 12v+ constant)

OR

B. It uses the "stereo" style power setup with the 12v+ constant for low-amp memory retention only, with the main power being through the 12v+ switched (so high amp draw would be through 12v+ switched).

That said, based on what way the LXCC is wired, just be sure to isolate the "main power" wires for each accessory; in most cases the memory wires don't draw enough power to cause noise. Ee: my old setup had the head unit 12v+ switched wire isolated from the EDFC 12v+ switched wire, but the EDFC 12v+ constant (for remembering my presets) was spliced into the OEM head unit 12v+ constant. Bear in mind the EDFC was wired directly to the 4 electrical motors on top of the shocks... but nope - I had no electrical noise.

Sc300i6

Hey man I did exactly what you stated on this thread but for some reason I get the head unit on at all times. Even with the key not being in ignition switch I also notice that if I unplug the antenna that's the only way it goes off. Here is my number 8055589572 if you can call me to better explain..thanks

raine

iTrader: (7)

You might have your 12v+ and ACC wires switched.

shauns

Raine. I do alot of custom installs. The fact that you were awesome enough to go out of your way 7 YEARS ago and do this thread up for everyone is amazing. Best thread I have EVER read online and way too good for just a thread, should be in a manual. The fact that you are still helping people too after all this time only shows how I am right about you and for you doing this in the first place. Ignore any "person" who throws negatives your way because they could never be you ... FACT. Thanks for doing this and helping so many with this. My hat is of to you.

raine

iTrader: (7)

As long as it's still in my memory, I help when I can

ar3

I'd also like to thank you for writing this up man. I bought my 97 a month ago and took apart the head unit and the previous owner did exactly what you did so I'm confident it wasn't a hack job.

raine

iTrader: (7)

Glad to help buddy

mrmax512

I used Metra Harness but not for sub amp integration. I just hooked up the RCA like above. But I made my own RCA to speaker wire by using the shielding as ground and the middle wire as positive. This is on a 95 SC 300 with Pioneer system, 155K. Thanks for this post!

raine

iTrader: (7)

no worries, cheers

krbrabeck

Has anyone done a writeup like this for an SC300/400 with the Nakamichi head unit and amp? I quite frankly don't want to go through all 38 pages of this thread to look, and if it hasn't been done, I'd like to do it. Any help would be appreciated. Please don't ask me to use the search feature...If I had tried that and found my answer, I wouldn't be here.

raine

iTrader: (7)

LOL quite frankly, if you don't want to go through all 38 pages of this thread to look, how about reading the first few sentences of the very first post:

dicer

When it comes to car radios I like the old stuff, just easier to work, I like ***** especially for the volume.

krbrabeck I'm with you on the search deal. I am amazed how it can't even find some posts I have done.
Its just so simple for a person to just say what it is, rather than waste the time and effort to say "search it".