If the meter does not jump when you turn the switch on and off then you likely have a lost connection. I have one OM-1md that the meter comes off its gimbal from time to time. I can get it back on by tweaking the needle with a toothpick (focusing screen out).
I do need to get that one in for professional help as it is otherwise perfect.
I don't recommend you abuse your camera the way I do mine. I only present my experience to show other things it could be.