UNCJD

After I screwed up and hooked the charging cables up BACKWARDS on my '95, I had to get a shop to bail me out. When I got it back, the speakers only worked on one side of the car. I was thrilled, because before they hadn't worked at all.
I had an exhaust leak that set a trouble code, so after I fixed that I disconnected the battery to clear the code. On my next ride, I noticed all the speakers were working.
I had an '88 Chevy where the system went in and out depending upon the bump you just rolled over. Suspect the same here, but could it be something other than a loose connection? Did the Nakamichi come with magical powers in 1995?

Yamae

LOL, but congratulations on your fix. I bet your problem must be caused by unwanted electrons reached and stored at the C-MOS memory and the processor since you have reversed the cable. Those were just erased and disappeared. May be you can call them unwanted elves sent by you.

Your 88 Chevy must have a bad connection inside. Don't expect elves. It's you or a technician who can fix it.