garnerm91

What wire from the stock radio tells the amp in the rx300 to turn on? Is it like a normal amp and just gets a small signal to turn on? or is there a relay or something else that turns it on?

basically I have gutted the multi disk changer and used it has a housing for my new head unit. So i have a nice bluetooth radio hiding in the glove box. The issue is I can't figure out how to get it to turn on the stock amp and I really don't want to rewire all the speakers. as of right now I have to turn on the stock stereo to get the speakers to come on.

salimshah

Welcome to club lexus.

Maybe a bit late to do the needed home work.

Lexus uses proprietary Serial link to control and communicate various audio components. When you gutted the CD, you must have encountered 2 connectors. One of them is the serial link connector.

The second problem you will encounter is that Lexus uses dual differential audio signals ... L+,L- and R+,R-. Standard audio has L,R and Ground. One can tie the L- and R- to ground, but the signal level will get degraded and common noise will be amplified. [with the dual differential system, the common noise is cancelled.

Salim

garnerm91

I spent a few weeks doing homework on before starting and the only thing I could not figure out was the kick on for the amp. All the stock stuff sounds fine without the cd player it only had one connector to it. so is my best bet to just go out and buy a new four channel amp to avoid re running all the speaker wires?

garnerm91

So I figured out what to do for now. Since I was already was leaving the stock radio in I just used it to control the amp and wired the front left/right into the R+/R- and L+/L-. It isn't perfect but works great for now and $150 cheaper than buying a new amp. So I got Bluetooth for $99.50 investment and about 3 hours of work. most of the time was just me being slow/drinking. If anyone wants details on how this was done I can post I know it was a pain for me to find all the resources I needed.

Edit; If the amp ever dies or I ever want to add anything I will come back and add a real amp and run some new wires but as is it works pretty good.

gazi001

Wish you good luck.