Audio problems, QX4 amp location?

[Mike W.]

'03 QX4. Aftermarket Sony stereo installed before I bought it 7 years ago. Working fine until couple of months ago I had a dead, dead battery after sitting for not as long as it has, 2-3 weeks, and after getting it started I was missing audio from the drivers speaker. The worst one to lose!!!

So far I've tried to read voltage going to the plug to the speaker and got nothing. I've pulled the head unit, thanks Sony for one more only Sony application, swapped out the RCA plugs on the back and still get nothing. I believe there is an amp at the speaker, I've got 12V there on red and black I believe it is, but nothing on the blue wires, which appear to be the speaker wires.

Is there another amp somewhere that might have a failed channel? A wiring failure between the head and the door? Possible, but it was working fine, nobody had been in there, so it seems unlikely. The dead battery may be a red herring, but I measured ~70ma on it, key off, which is high. Not crazy high, but high.

Any thought would be appreciated, especially if there is another amp somewhere, and where it might be.

[Mike W.]

There does not appear to be an amp or anything inbetween the head unit and the front speakers. I ohmed it out and it was pretty much zero. But since it was a preamp output I wasn't really reading anything, maybe .3 volts, AC. New speaker assy with the amp built into the assy fixed it. Yaaaa! Sounds on my side again.