I just recently purchased a 94 sc300. All the audio system is original(pioneer unit) but for some reason the volume is very quiet. Even at full volume I can just barely hear it. Is my amp dead or maybe the volume control is not working?

Thanks,
Chad

 

Does your SC have or have ever had a dealer installed Lexus phone? The reason I ask is that corroded connections at the phone ECU in the trunk can make the radio go into mute mode - a very common problem. If there is phone ECU in the trunk, unplug all the connectors from it. If there are two large connectors that will plug together, then plug them together.

Even if your car has never had a Lexus phone, it is rare but possible that the mute at the amp is corroded and grounding.

Dealer installed Lexus phone systems automatically lowered the radio volume and sometimes the HVAC fan speed while a call was in progress.