90 marathon sparked when I turned the key

[90marathon]

I installed the batteries in the cart as I was told when I got that it ran. I also got a 77 ezgo from the same person and once I installed the batteries it ran perfectly so I trusted this one would also. I did use a wire diagram found on pinterest with this site being listed as the source. when I turned the key the ignition switch itself sparked and it looked suspect anyway before I tried but is now burnt completely. I installed the switch from my 77 ezgo then the orange wire running from the solenoid to ms3 normally closed burned up. I then double checked the wiring and found the blue and white wires running from the speed control to ms4 on the forward/reverse were crossed. I fixed that and tried again. then it sparked across the solenoid and blew what I believe is a diode. What should I try next?