I installed the battery backwards on a 2007 zg20 with Kohler CH20s engine. I tried starting the mower multiple times before realizing what I had done, yes I know stupid. After switching the posts I tried starting it again, it started and ran for about 2-3 seconds before shutting down. I realized the 40a slow blow fuse was blown. With the fuse removed I ohmed out both sides of the wire, the side connected to the 15/20a rectifier is shorted to ground, when I remove the REGULATOR/RECT 12/15A-(#2540345S) the wire is open. I am not certain if the rectifier is the issue or not. I really do not know how to check it. If I remove the recitifier and short the solenoid the starter turns but does not engage the flywheel.