66 Chevy K10,Odd wiring problems

[66K10383]

Hi, I have a 1966 Chevy K10 pickup.there have been problems in the past with minor wiring issues like the starter wiring harness grounding power to my coil.
Thankfully I was able to fix that with the guidance of this site and my truck has ran great until last night.

I was on my was home from work and my stereo cut out, it lost power but the backlight was still on. its happened a handfull of time before but always powered up seconds later. Well, this time it started flickering in away that would make my truck stumble and act like it was running out of gas. I stoped and looked under the dash near the stereo to find my heater control plug half plugged in. I pushed it all the way on and fired up the truck. the problem seceded for about 3 miles then out of nowhere(to my knowledge) my stereo cut out again and all my guages would jump in a rymithic "pulsing" pattern almost at the pace of a blinker relay. While doing this my truck would run in a flowing Rommp,rommp rommp. pattern with the gauges.

I dont know alot about the old Chevys but I willing to learn. My only thoughts are maby ALT?? or voltage reg?Hopefully that makes alittle scence.

Thankyou