I recently changed the battery and both battery cables in my 1997 3000gt SL. It is getting power just fine, but it won't turn over. Any suggestions?

My 91 did that. It was in steering colum. Lower steering wheel all the way down. Wiggle key up and down as you turn it mine would turn over and crank that way. That is if your lights on the dash are coming on as they should now. Need to replace my switch. If that don't work check brake and clutch switches

Previous answer was not my problem. Loose selinoid wire on starter. Fixed connection and problem went away.