It sounds like a main electrical connection is failing like a battery cable is going bad or is loose. Here is a guide and a diagram (below) so when it is acting up you can do some testing.
See where the system is loosing power so we can go from there. Also pull on the battery cable to see if the car acts up as well.
Please let us know what happens, we are interested to see what it is.
Images (Click to enlarge)
Saturday, June 24th, 2017 AT 11:31 AM