I'm not sure if the amps have any indicators or lights at all, they were in the car when I bought it. The front one is behind the interior clothing, but I can have a look at the rear one, see if it appears to be on.
As far as I know, no wires were anywhere near the seats... at least the front ones. A friend built in the rear ones, the cabling for the rear amp does pass where those are mounted. I'd
reckon he'd not be stupid enough to screw right through a cable though.... but heck, will have to check
If any speaker wires are grounding, that would be a poor coincidence I guess... it's hectic at work atm, but I hope I can find some time to look into things this weekend.
Is there a quick and easy way to 'error check' the car stereo itself?