I installed a Z110BT into my Miata about 3 months ago. This was a 2nd install - I had it in my previous car. So I bought an aftermarket power harness (non-Pioneer) and AV harness to do the 2nd install (all the other wiring was stock). I have had zero issues with the AVIC up until about a week ago. I am experiencing a temp drop in sound (complete loss - not a mute) where I will lose sound for about a second, and then it will come back on. It does this randomly and doesn't seem to be related to the unit heating up - although it is fairly tight back behind the stereo. It will do it a few times in succession and then it won't happen again for a while. I have also had it happen right when I start the car, so I really do not think it is heat related. I can turn the volume up (and bass) and not have it cut out. Also important to note is "ATT" does not appear when this happens, and the issue occurs regardless of what input I am using, CD, ipod, etc. One other thing, if I hit the side of the center console where the stereo is installed, I can replicate the problem.

Here are my thoughts on possible causes:

1- it is a loose wire on the aftermarket AV or power harness. If it was the AV harness, what are the odds I would lose sound to both speakers? If it was the power harness (bad power or ground connection), the unit would shut off right? But my unit doesn't shut off when this happens. ANd why would this happen now after months of running fine? Is there another wire on one of the harnesses that if it was loose could cause this issue?

2- it could be the unit itself. Just something wrong with the unit and not related to overheating.

3- the unit is overheating, and just not displaying ATT when it overheats. Again, I don't think this is the case because when I came out of the grocery store and started the car, it did it right away.

4- i am running the line level outs from the AVIC to a Bose amp which could be overheating. If I couldn't replicate the issue by rapping on the center console, I would consider this as a possibility. But I think I have eliminated this as a possibility.

5- recently (not sure when but within the last month) I cranked up the brightness on the unit so I could see the display when I have the top down on the Miata. Could that be heating up and cause overheating without ATT displaying?

I plan to take the unit out and jiggle wires with it turned on to see if I can narrow it down to a loose wire. But I thought I would see if anyone had insight before I tear the dash apart.