ShapeShifterz

Hi,
Im trying to get a panasonic 592u hooked up to the stock amp. I connected the L+/- and R+/- to the panasonic's RCA outs but it doesnt sound like the amp is getting any power.

Since there are only two channels coming out of the stock deck, im assuming the fading function is done by the amp via the TX+/- signals. I was thinking the AMP+/BU connection needed 12+ volts but I didn't want to risk it just yet.

Anyone have any suggestions? Here is the schematic again:

Stock Deck-Amp Schematic

Thanks

LS007

With the stock IS300 radio in place, I'd measure the + voltage on the AMP wire (White w/light blue stripe) with reference to ground. If it's 12Volts when the radio is ON you can then feel comfortable connecting the 592U using the Panasonic remote amp turn on wire to the amps white w/blue stripe wire. It might be a difficult to match the Panasonics RCA pre-amp outs with the stock amp inputs. Without the control protocol on the TX+/TX- the amp may not even function. For this reason and matching pre-amp to amp levels wouldn't it be easier to wire the 592U speaker outputs directly to the speakers?

One thing that is kind of odd about this schematic and might be in error is there is a SGND (Signal Ground?) and still a - for each CDL or CDR (stereo player) output. Could it be that all the CDL and CDR wires are low level + and there is one L/R set for front speakers and one L/R set for rear? When your stock radio is back in for testing the remote amp turn on wire, disconnect each of the CDL or CDR wires to see what speakers go out. This will tell the true story.o

Percy

One set of L/R outs is for the radio, the other set is for the CD. Fader is controlled internally via the amp (NOT the HU!) by the TX signals. That's the control protocol which tells the amp the fader levels, etc.

Best bet is to get yourself line level converters. Otherwise if you switchover from cd to radio, you'll lose the signal without some sort of relay network. A real pain.

Percy

ShapeShifterz

@Percy:
I think you misunderstood - I want to ditch the stock deck but keep the stock amp. Regarding the separate CD/radio inputs - my headunit has 4 RCA preamps so shouldn't that be irrelevant?

Do you happen to know if the amp will work without the control TX wires?

Thanks again.

Percy

You want to keep the stock amp?

Ewww....

You already have an aftermarket HU...get an aftermarket amp. The system will be much better with an aftermarket amp.

Percy

ShapeShifterz

Well, im pretty content with the way the stock amp/speakers sound. Im also trying to avoid rewiring the whole car just for a simple setup. I'd have to run power wires, longer RCAs, and speaker wire going to the components. On top of that, i'd have to worry about crossing them over.

DJ SprinklesNJO

wow ive never heard of someone replacing the stock HU and not the amp. you did the hardest part to change in a lexus (HU) now just run rcas for an amp. but hey do what you want. its cool with me. i got a question............
where did you get the wireing schematics for the is300 amp? can you get me a diagram for an RX300 (2002 with navigation if it is differnt) or tell me where i can find one. thanks


also another quest, maybe percy can help me out. do you knopw if the stock sub frequency is cut off towards the lower frequency range? the rx300 has a little 5'' sub and i cant imagine the stock amp and HU send the full 20hz band to it? what does it cut off at? like 60 or something?

ShapeShifterz

Actually the stock deck on the IS300 is super easy to take out. Like I was mentioning, its running the wires for the amp to the trunk that are the hard part. The stock amp also crosses over at 3 frequencies so I didn't want to lose that function or worse replace all of the speakers.

The schematic came from the service manual that someone scanned and posted on .NET. I'm pretty sure that you could call up your local dealer and ask them to fax you the relevant page for your RX.

DevilDog

Unfortunately the Wire Diagram is only 1 of 2 pages. Do you need the second page? PM me your e-mail and I can send you the whole thing.

DD

NDCENT1

Just wanted to throw my 2 cents in here and let you know what I have found. I wanted to get rid of the factory deck and keep the stock amp for the reasons that you mentioned. I have done alot of research on this and have found that the factory amp gets a digital turn on from the factory head unit. I have a buddy that did it on his 2000 IS and got it to work, but it seems that they have changed it for 2001. I even got the Scosche adaptor and I also have one of the first prototypes of their new dash kit. Dash kit works very well and looks nice. The plug for the harness works well but there is no way to get the factory amp to turn on without the deck. Sure you could dismantle the factory head unit and use the guts and most likely make it work but I have spent so much time on the phone with people from Scosche and also from Soundgate that they have confirmed that it uses a digital turn on. I just ended up installing a 4-channel amp for the fronts and the 6x9's and use the deck power for the rear speakers since they are pretty small. Did not want to put subs in as you know how small the trunk is already. I did not want to give up ANY space for a sub enclosure. Maybe in the future I will do it but as for right now it is just not an option. Hope this helps you out in decideing as what your game plan will be.

s4play

iTrader: (2)

NDCENT1: So if I'm reading what you said - you CANNOT install a aftermarket CD player (Kenwood) without replacing the oem amplifier too???

I'm installing a cd deck but we do NOT want to touch the stock amp or speakers....there must be a way???


rick