When driving for a bit at 70 mph. Headlights, dash lights, and radio start to cut in and out. Alternator has been replaced. When idle I've tested the battery and alternator stationary, everything turned on, and over 2000 rpms. All pass.
I also have this other issue where everytime I get gas my car wont start, it takes a minute to crank.
Could the fuel pump drawing too much power cause this issue?