[djmcmath]

I'm getting nothing on Google, searching through forums, or asking my tech-savvy friends. I thought I'd check here in PPOT in hopes of a surprisingly obvious piece of information that I've missed.

So here's the data:
- The audio to all speakers intermittently stops, then restarts, as if I've put the stereo into "mute." I can draw no correlation between when the failure happens and any kind of external input -- changing source (bluetooth to FM to AM to CD), unplugging and replugging speakers, opening or closing doors, temperature, or anything else I could think of. I can't make it fail, so I don't understand why it's failing.

- It is an aftermarket head unit, a Blaupunkt 420BT, installed in my 2001 BMW. It worked great for perhaps 6 months before this started.

- The obvious guess is a ground wire, but if it was a bad ground, I'd expect rough audio or overall power issues.

- After a bunch of research, I discovered that some head units have a feature where they shut down all audio output if there's a ground on any speaker wire. Given the age of the car, this seemed liked a reasonable possibility to investigate. So I installed switches in all 8 of the speaker wires and waited for the problem to happen. If this was the issue, I should have been able to isolate it by simply opening the switches to the grounded speaker. No such luck. The problem came and went, regardless of which speakers were connected.

Any thoughts? I'm at a loss here.

Thanks,
Dan