popping and cracking while engine runs

[70chevellemalibu]

i have a 1970 chevelle fully restored and i just put in a new Kenwood deck. I used the factory yellow power wire and factory ground for the stereo connections plus a new wire to the BATT terminal on the fuse block, all wires are soldered and heat shrinked. I do not have an external amp or any RCA's.

When the car is off the stereo sounds pretty good its not a ground pounder but it sounds good, i start the car and i get the popping and cracking/delayed music almost like a CD is skipping, this sound occurs with FM, AM, and USB. I have already tried to disconnect the FM antenna, i have removed the deck from the car and moved it around and i get a very minor improvement. The sound does not change with RPM.



I have also tried a different ground location and still no change.

I should note that the car has GM HEI and has steel braided cables that do NOT have ground cables, i shut the lights off in the garage with the car running to see if they were arching and I didnt see any sparking along the headers or firewall.

I have read some online car audio threads and the all seem to be a bad ground or RCAs.

Does anyone have any suggestions?