hazard light switch acting up ('84 308)

I am puzzled with this one and would welcome your expertise. While testing the parking lights I notice that the driver's side blinking was not always responding (front and back and also on the green indicator light in the speedometer)... To my surprise all bulb contacts were OK and I finally realized the problem may be related to the hazard switch itself : when I pull the round black switch level a little stronger towards the back (in the ON position)the problem disappears! I cannot reach this switch from the ashtray pit and the wiring diagram shows 5 wires getting to this mysterious switch... Is it a loose wire /faulty contact or the switch internals itself? How the heck can I get to the little sucker? Any idea? Thanks ...