Car Stereos: Stereo turns on but no sound., rca line, pioneer mp3

Question
Hi, I recently bought a car that has a Pioneer KEH-P2035 cassette deck with CDX-P680 cd stacker. The HU turned on but no sound. I took it all out to test. The two negative wires for the front channel were joined together and taped, so i separated them. Why would somebody do that? I powered it up and tried a speaker on all four channels, no sound. I connected the RCA line outs to my home stereo AUX in and it plays. Do you know how this is possible? I tried all functions of the HU and the stacker and everything works. I could possibly use an external amp, but i don't own one. Is it the amplifier has blown from the crossed wires? What components would most likely be damaged? Any ideas of the cost of replacement components? I would like to get it repaired. (either fix it myself or repairer.) Thanks for any help.

Answer
Hi Stuart,

Connecting two negative wires together generally won't harm anything (unless the positives are connected too, which would result in too low impedance, thereby frying the internal amp), but even if that's all you found, there's a possibility that whoever had it did other shoddy wiring that fried the internal amp in the deck in the first place.

That said, replacing the KEH-P2035 is your best option, as repairing it would cost more than the deck is worth (and the deck is only worth about $5.)  You can buy an aftermarket (even a replacement Pioneer MP3 deck) for about $100 brand new.

The other alternative is to just use the preouts and install an amplifier, but that's a lot of work.

Good luck,
Justin