So for a few years now my Suburban has had a very intermittent electrical issue. It has happened a few times while driving but mostly when its off and I'm getting out or getting in the car.

The issue is complete loss of power. Like no battery power.

The few times it has happened when I'm driving the engine shuts off and all electronics shut off. When it happens and I'm not driving, all electronics shut off like there is no battery.

When it first started happening I could go and wiggle the negative battery cable (wiggle the cable as the terminals were tight) and the electronics would come back on. So I replaced the cable and the problem went away for a while.

Then it came back. I could go and wiggle the cable just a tiny bit and the electronics would come back on. There was even one time I opened the hood and got close to the cable but didn't touch it, and the electronics came back on.

I've taken apart both positive and negative cable and cleaned every connection and put dielectric grease on every contact but I still have this issue.

I've tried to replicate it losing all power but haven't been successful. I only happens on its own.

Any ideas where I should check?