I have a 2008 Lexus RX350 with 160,000 miles on it.

All the time when I turn on the car by turning on the key from OFF to IGNITION without stopping at ACC postion, I don't hear anything from the speakers. (I believe the Amplifier doesn't get engaged). My radio turns on but no sound.

I will turn off the car and then turn the key from Off to ACC position and wait 3 to 4 seconds before turning it to the ignition, Now I can hear everything from the speakers.

Has anybody else experience the same issue. Why the amplifier kicks in at ACC only after waiting 3 to 4 seconds.

 

I can only think of 2 options...

#1) wait and see what hapens- maybe the failing part or bad connection over time will get worse or die and be easier to trouble shoot.

#2) Pull the back seat on passenger side and do some voltage tests at the amp to see if the voltage is "instant on" when keyed to ACC mode or not.