Trying to test the shift switch on my 1990 Evinrude 200 outboard. I understand it should test just like an on/off switch, if depressed it should show continuity basically grounding the power-pack and open if not depressed. My question is, should it read on a DMM just an infinite(open) when not depressed? I'm measuring a little more that 550 ohms and not an open reading, if I depress the switch it do show continuity. Is this measurement indicating a faulty switch?