mph1970

2 months ago I went to start my suburban and nothing..no click, no noise, nothing. I turned the ignition on and off multiple times and it eventually started. Several weeks passed and it happened again. On the advice of a friend I replaced the starter. This morning, it happened again. I took a test light and tested the starter (big lug) and it was fine. I had a friend turn the ignition and I tested the ignition wire on the starter and it was fine. I placed the tester across both lugs and the starter turned. Any suggestions? Thanks.