Audio Systems: Stereo Installation, toyota tercel, speakers system

Question
Hi Cody,

I have a audio problem that you might be able to help. I have a 92 Toyota Tercel with the factory AM/FM cassette radio, four speakers system installed. Nothing was wrong with this radio, everything worked fine I just wanted an updated stereo to play my CD-R/RW. I purchased a $100 cd stereo from Walmart, don't want to spend alot on a system to install on my commuting car. Here's my problem:

I purchased the stereo and correct connector kit, I installed the stereo and everything worked fine for three weeks. Then, one day the audio stopped. All the functions, modes, displays still operates, but there is no sound from any of the four speakers (connected individually). I checked all the connections and ohm all four speaker wires and everything checks good.

So, I removed and exchanged the stereo and reinstalled the new stereo. Worked fine for a week and again, the same thing, the stereo has power and all the functions work just no sound from all four speakers. Some days I can use the car and the stereo will play like nothings wrong and sometimes it will go 2 weeks with power and function, but no sound.

Just today, I returned the stereo and purchased another stereo from Bestbuy $135, installed the new cd stereo and it worked all day, the next day, again there's power and all the functions work but no audio from any speakers. The system is installed correctly GND,ACC PWR, Memory PWR, RT FRT SPK, LT FRT SPK, RT REAR SPK, LT REAR SPK wires connected, it doesn't blow any fuses, the speakers are rated close to the stereo rating (speakers came out of my 99 Dodge Ram), it just has no audio output.

This new stereo is a JVC KD-G200, 200W, 2Chnl, Max pwr output 50W per chnl. The other two stereo's were of similar performance.

Any idea what is preventing the audio output from all four speakers?

Could there be some kind of factory thermal switch installed in my car?

Thanks for your help,  

Answer
Del Makio,

 
 try exchanging your speakers you have already tried the head units and they all seem to function pick up a set of aftermarket speakers in the range of 20-40 a set so 2 sets will put you well under the mark of a new head unit install those and then see how your performance is .. since you have checked most everything i would have recommended ohm/wire/fuses ect.. this is the best solution i can offer.. that and retrace all your wiring to make sure none of the speaker wire is pinched or in a hard bind that might make the sound cut out or cause distortion.. hope this helps you out if you need anything else let me know

thanks