Have you lost EVERY SINGLE punctuation key from your keyboard?!
It sounds like an intermittant bad earth to me - check the earths to the battery, from the engine to the body, including the strap that should go from the back of the head to the back of the engine bay and also the little basket of earth connections up under the dashboard, above the fusebox.
Take the ones in the engine bay off and clean them and inspect them for damage.
Visually inspect the ones under the dash and give them all a wiggle to make sure they have good contacts.