hardin1271

So... it began with my wife driving and not paying attention to where she was going. Eventually she got to the point where she felt the front left tire deserved to be slammed into the median of an upcoming fork in the road. Tire blew out. Rim was ok. Got back in to continue the drive home and there's no sound. And so the journey begins. I'd like to, hopefully, help some people out by reviewing everything that I researched and/or had checked and what, ultimately, was the resolve for my issue. Keep in mind that it took almost 3.5 months to get this properly diagnosed and fixed.
When I say no sound, I mean NO SOUND. Not from anything: stereo, CD, Bluetooth, phone, navigation... zero, nada, zilch.
Here's what I discovered was the issue.
Possibilities: Amplifier, Cracked wiring harness under feet, blown fuse, blown fuses, blown speakers, damaged plugs into amplifier, radio head unit, audio connections into steering wheel damaged.

Went through every single fuse in the car that might have the slightest relationship with audio and changed it. Not it.
Amplifier is located under the driver's seat. One thought was the impact from the hit was hard enough that it damaged the amp in some way.
New amp from Lexus IS sound $1500. Bought one off eBay for $500.
That amp didn't fit so if that is your issue make sure that the Seller has pics and that it is the EXACT model number. Some make look like they'll fit, but there's a little notch in the plug that's difficult to see on a pic.
Sent my original amp to United Radio and they called and said the amp was fine. If you have no doubt that it's the amp, I highly encourage you to take the easy way and just send it to them. They are the best in the business with quick turnaround times.
My mechanic couldn't get anything more than a generic read on the diagnostic.
Car audio place was able to dive in deeper to the connections of all of the components, but everything checked out fine.
I did learn from them that speakers in Lexus model cars have a unique feature. When one speakers goes out, they all stop working. My speakers were okay.
Also discovered the reason why the amp can't be switched out for a new amp from Crutchfield or somewhere else is because Lexus, like most automakers, has their own proprietary communications system and every part of the communication is digitally run through the amp. Some people have done workarounds to put in different components, but have come back to say it wasn't worth it and they wish they'd left well enough alone.
I finally broke down and realized the only option to get the most detailed diagnostic was to go to the Lexus Dealership. I was expecting a diagnostic fee of a few hundred dollars, but ended up walking out with the answer to my problem for only $94.
My issue ended up being the radio head unit. The impact was hard enough that it knocked one of the chips loose.
Found one on eBay for $250 and same car stereo guys installed it for $59.
New radio head unit from Lexus was $2500 including labor.

If you end up with this same issue, I hope this info helps. There are a lot of variables. I enjoy the diagnosis, but this time the frustration was high and the length of time was extremely bothersome. If I had it to do all over again, I would have called the dealership and checked what their diagnostic fee is. I had made the assumption that it would be several hundred dollars, but had I done the proper research, this issue could've been resolved in less than a month.

Good luck