1995 Hyundai Accent Starter solonoid

I removed starter opened it up and checked both it and solonoid on my work bench...by providing necessary 12V + & - hook-ups and by jumping 3rd solonoid lead...worked perfectly on the bench, however, reinstalled unit into the vehicle. Starter immediately cranked engine over and engine started on the first attempt. Shut it off and attempted to start engine a second time. On second attempt only starter armature activates...solonoid failed to engage
bendix to engage with flywheel. I can hear the starter operating properly but it will not crank the engine. Could the problem relate to the egnition switch itself and not the starter? Please advise