I just bought a used 2010 Lexus RX350, without navigation, 135k miles. I didn't test the audio system after bought it. Then I replaced some light bulbs with LED. Noticed that the battery is about to die. I replaced the battery. Then I realized there is no sound from the audio system.

The symptom is: every button seems to work as expected, including the volume **** and the volume button from the steering wheel. When I turn the volume ****, the corresponding volume level displays on the screen. But there is no sound.

Here's what I've done to troubleshoot:
1) I checked the AMP1 and AMP2 fuse in the engine compartment. They are good.
2) I checked the RADIO2 fuse in the cabin on the driver side. It is good.
3) I disconnect/reconnect the supposed-to-be head-unit-to-amplifier harness under the center console, per https://www.clublexus.com/forums/rx-...-of-audio.html. I disconnect and reconnect both the grey and the black connectors. Makes no difference.
4) The vehicle has a SOS button on the map light assembly. Both lights are off. Per the user manual, this means no service. I press the button, there is no sound.
5) I disconnect the negative terminal of the battery, wait for 20 minutes, reconnect it. The time resets but still no sound from audio.

I guess the next step is to check the audio amplifier, which is located in the trunk area behind the 2nd row seat, on the passenger side. I know how to get to it. But once I get access to the amplifier, how do I diagnose it? I know how to use a multimeter. But I don't know how to test the amplifier to see if it is good or bad or not receiving voltage/signal, etc.

Any instructions, videos, articles are much appreciated!

 

You may have a dead amplifier. See these threads for more suggestions related to this problem.

​​​​​​https://www.clublexus.com/forums/rx-...st-resort.html

https://www.clublexus.com/forums/rx-...io-issues.html

https://www.clublexus.com/forums/rx-...amplifier.html

​​​​​​https://www.clublexus.com/forums/rx-...-no-sound.html

​​​​​​https://www.clublexus.com/forums/rx-...rx-350-ii.html

 

@Clutchless, thank you so much for the links.

Is there any quick tests I can run to make sure the amplifier is the problem? The reason I asked was:

• One of the Lexus owners had similar problem. He purchased an amplifier but never got to use it. Because he found out it was one of the speaker that has bad connection and caused the original amplifier to act up. After replacing the speaker, the original amplifier works just fine.
• YouTube shows that some of the Lexus models (with navigation) has a hidden menu to run amplifier tests. It can tell if the amplifier is good or bad.

I was trying to avoid buying an amplifier then find out it was not the problem. It could be a connection problem, a speaker problem, etc. Any further suggestions are appreciated!

 

I do not know how to test the amplifier. Electronics are not my area of expertise.
I do know that you can test a speaker by connecting 2 wires to a battery then touching the wires to each speaker to determine if it is working. There are probably youtube videos demonstrating this test.
Using the search feature here is easy and may help you find out more regarding amplifier testing. Or maybe check out the audio specialty forum linked below.
​​​​​​https://www.clublexus.com/forums/lex...lectronics-12/