Hello,
I have been digging through numerous threads on how to bypass the amp on an LC and I can't seem to find any instructions. There is a lot of info but nothing that is solid on how to perform this task. Has anyone done this before and if so could you please provide the steps needed to make this happen. Can you also provide what additional equipment you used as well; harness or audio control unit LC6i or 7i. Heck, I would be willing to send you a 12 pack of some Colorado craft brew or a gift card for your time, lol.
Thx.
I thought like you did originally. I didn't understand the amp bypass metra harness thing, or what it was used for exactly. I understand it now, but I don't think it works for the 2006-07 100's. I am deeply into the audio on the 2006 LC.
If the end goal is to leave the stock headunit and the stock amp in place, and bypass the stock amp and mount another amp somewhere else then that's what the "amp bypass" implies, right? so the metra should plug into the stock radio and output all the speaker lines to where ever you want. That harness is very long. more than ten feet. Then you have high level speaker leads from the stock head unit. I assume we're talking about this harness
Amazon.com: Metra 70-8116 Factory Amplifier Bypass Harness for Select 2000-2004 Toyota Vehicles with Amplified JBL System: Car Electronics
I found that harness pretty useless. I did use the smaller plug that goes straight into the female factory plug later on down the road. But that was for a different head unit. I used the red and yellow to get +12 and batt power
It is much easier to just pull the speaker leads AFTER that stock amplifier, on their way to the speakers themselves. From the stock amp you get the passenger front, both rear door speakers, and the sub. (dual wiring) the drivers side front has to come after the NAV ecu processing. That's where the voice over control for navigation comes from. (pink and purple wires).
Then you'd take your speaker leads, (12 I think) and do what you will with them.
Install another amp and use high/speaker level inputs into another amp on the input side, this would be out from the stock amp, into the input of the new amp.
Then the leads that go to the stock speakers would connect on the output side of the new amp.
In the case of a digital processor like the audio control units, and others, you're taking the speaker level outputs of the stock amp and inputting them into the LCI or whatever. Then the processor does it's thing and outputs a low level signal to how ever many channels you need that make it possible to connect a multi channel amp on the input RCAs as a low level signal. Hoping that the kind of expensive processor outputs a clean, noise free signal allows you to install an amp as normal.
The processor just cleans up toyotas funky signal grounds and outputs a clean low level signal.
I don't know of any harness that will allow you to bypass the stock amp, from the stock stereo. Maybe the metra does and I just don't understand it. But for me, I'd rather eliminate wires, not add to them. IF you read a lot of threads, people end up with serious ground noise. If that happens you still have to go back and fix things again. Which is what I believe happens because of the ground issue.
It depends on whatever your end goal is I believe. I wanted to ditch the stock headunit. SO adding another harness to the back of it didn't make much sense.
To me, if you're going to the trouble of a processor, it doesn't make much sense to add any metra harness.
Maybe you know all this already, idk. hopefully it helps you some. If you need any pictures of the EWD for a 2006 which I have heavily used in my stereo testing and installs, let me know.
I have quite a few stereo threads that I've started. There is info in them that might help you.
