97 Z24 Dash/Headlights/Stereo Problems

I own a 97 Z24 that I’ve had since November. Driving last Sunday, the dash lights all flashed on (like when you start your car), and the stereo (stock) went off, just for a brief “flash”. This has continued to happen since then. The battery is new, tried it with a new alternator, same result. There has only been these “flash’s” except for 1 time when the dash did not work for about 2 minutes, only my temp. gauge and gas gauge worked on the instrument panel & I had no stereo or headlights …Yet my power windows and windshield wipers worked. Once only, my stereo lost power, for approx. 30 sec, and all the dash lights were still working, they then “flashed” on again … and my stereo came back on. I have had a mechanic look at it and can “coax” the dash to “flash”…sometimes ...by having my A/C on, stereo turned up, and after a few minutes turning on my headlights, but this doesn’t work all the time. This will happen also without a “power surge”, I’ve put the car in reverse and it’s happened ...driving with the stereo off and the A/C off… it's happened, but not as often.
Thanks for your help.

Found it...Main wiring harness from wirewall...loose/melting connection.