Deception

iTrader: (1)

Hello fellow members, im wondering if is there a bypass for the amp that anyone is using. i searched the fourms and found that the factory amps are not bypassable.

i found an amp bypass, but was wondering what is your input of what you guys have or how you guys did it.

GS4_Fiend

iTrader: (22)

You don't bypass it, you are suppose to join it with your new amp.

CK6Speed

iTrader: (1)

You just have to run your own wire and wire it up yourself. I personally don't like to keep the factory amp in line with the aftermarket amp. Reason being is when your OEM craps out, and it will crap out eventually, you loose the signal to the aftermarket amp as well. It really makes no sense to amplify, attenuate, then reamplify the audio signal.

Deception

iTrader: (1)

most searches ive done said that you get the metra harness and extend it to the amp in the glove box, and then you use a test light and find the wire for the speakers. but then this doesnt make the amp work.

for example this:
http://www.lexusownersclub.co.uk/for...howtopic=52551

well i found a like a amp interface that might work. but i guess i'll be the gunneia pig for this.

http://soundgate.com/index.php?reque...usereferrer=1&

"The XR4 is an adjustable, high-performance, dual-purpose, 4-channel device which functions as a Radio Replacement Interface in amplified systems, or as a Line Output Converter simply by switching the XR4 output harness (included). With full DC isolation, proprietary transformers, and elimination of power resistors, you get 20 Hz to 20 KHz frequency response, and no noise! XR4 can easily handle up to 85 watts per channel of power."

macd7919

iTrader: (10)

Two ways to go about it:

1) Run the speaker output wires from your radio down to the amplifier behind the glovebox, the ones you want to connect to are the heavier gauge wires. Some of the colors on the factory plug will be pink, blue, purple etc... if I remember. Easy way to tell is that the plug leaving the factory amp is the same as a Toyota radio harness. So really you can just unplug the connector going into the amp and use the speaker portion of a Toyota wire harness. Using that method you will bypass the factory amplifier but you will lose the factory subwoofer output.\ unless you get creative with your new radio.

2) If you want to retain the factory amplifier you will need to find the input wires behind the radio. You should be able to find them with a multimeter and your old radio turned on by measuring voltage on each channel (you will see an increase of voltage as you raise the volume etc...use the fader/balance control to narrow down each speaker). One you have done this take an old pair of RCA wires and cut them in half. Strip the wire back, the very small wire in the middle is the positive wire and the outside "shield" is the ground. Hook them up to the appropriate signal wires on the harness behind the radio then just plug them into the rca outputs of your radio. You can then use the radio with your Lexus amplifier and have the proper input signal, if you run the speaker outputs of the new radio into the pre-amp inputs of the Lexus amplifier you are way over-amplifying the signal going to the amp and you will have the common trait of an improperly installed aftermarket radio with factory amplification which is the volume is over-exaggerated, like when your new radio is only turned up to 5 out of 60 and the volume is already blasting.

3) As far as the subwoofer working with an aftermarket radio will take a little experimentation on your part. Basically what you can do is take a multimeter to the subwoofer inputs at the subwoofer in the back of the car, set the meter to "continuity" and test for continuity between the subwoofer wires at the amplifier behind the glovebox, once you fine the correct wires you can use a small battery (9 volt or drill battery for instance) and "pop" the speaker to make sure you have the correct wires and phase. From there just hook up the subwoofer channel accordingly.


BTW: You don't need that $99 thing, if anything I would take the $99 and have a GOOD shop (Don't even THINK about Best Buy etc...find a good high-end shop in your area) install it for you if you don't feel comfortable doing it, OR if you fel comfortable doing it and have a few extra dollars, don't worry about testing for the subwoofer and spend the money on a small amplifier, say 100w rms, and use it to power the factory sub, you will get more output than you were getting factory and you wont have to worry about testing for the sub etc...

CK6Speed

iTrader: (1)

Also, not sure if its the ML, or cars with navigation, but my amp is located in the trunk on the passenger side. That would mean you just have to extend the wiring all they way back to the trunk if you are using aftermarket deck power. If you are adding new aftermarket amps than no big deal as you probably are mounting the amp in the trunk anyway.

@lpher

Throw away the OEM amp...

Gunbelt

The easiest way is to interface your head unit with the factory amp. Soundgate makes a product called XRTOYLEX which does that. The only other way is a complete gut of the sound system. Believe me I have searched. The crossover is done in the amp too. Funny how Lexus would make such a mediocre system so hard to work with.

Gunbelt

This is the best write up available for upgrading the factory system: https://www.clublexus.com/forums/gs-...k-40-pics.html

TANTASTYK

I instaled the oem radio in the trunk to turn on the oem amp and solve the problem for the factory amp turn on

likwidsoul

Have you used the XRTOYLEX and has it worked? Does it actually work for 98-01 GS's?