Audio Systems: Speakers popping

Question
I have a 2004 Toyota Sequoia and recently the stereo system starting working intermittently.  We took it to the dealer and they wanted to charge 4 hours of labor to find the problem.  I agreed to one hour and all they said was that it could be the amp or loose speaker wires.  I want to try and fix this my self, but I don't know where to start.  The speakers pop even when the entire stereo system is turned off??  They used to pop for a few minutes and then the system would work fine, but now it rarely works at all.  Should I start with replacing the amp?  Thanks for your help; any guidance is appreciated.

Answer
Sounds like an amplifier problem, but there is no way to test it you don't have the correct tools,
but the noise can also be send by the radio I seen more Toyota JBL Radios go bad

you need to pull the radio and see if there is any local shop with the factory amplifiers and speakers to test outside the vehicle
if the radio works you can replace the amplifier,

check here for the amplifier or toyota radio <a href=”” rel=”dofollow”></a>
Toyota Factory Radios