Ok so my door ajar light stays onand my side.

Ok so my door ajar light stays onand my side veiw mirrors do not work also the door lock button does not work. This is what I have found out, when I had the door open (front drivers door) I held the door lock button down while wiggling the wire harness that is going from the door to the cars body and the doors locked and the light for the door ajar although did not go out right away (door was still open) it didd go out when I closed the door and the mirriors worked, m but only until I shut off the car and opened the door. Since then I can only get the door unloch button to work but can not repeat the orginal result. So here is my question. What would be the most likely problem and what would be on your to check list to troble shoot to the end problem? Another question is that the gas gauge seems to be erratic could this be in conjuction with the first questions problem?