I double checked my battery cables twice to make sure I hooked them up right. Still did it wrong. 1983 70 hp johnson The rectifier is now shorted out. Any other damage?
You might have damaged the stator coils but hopefully just toasted the rectifier.
You could check the coil for continuity and once the old rectifier is disconnected check you get an output from it but otherwise replace the rectifier and then check all is well.