dont fell bad ,my stang would start by itself, after you drive it and shut it off the starter would kick in,si I ended up replacing the entire wire harness.
as for the dimming lights my be due to your alternator. take it off and have it checked, Orileey will do it for free.
also check had make sure a wire is not being pinched.
welcome back bro, I noticed you by passed my house thanks.lol