How to properly write defaults using AppleScript in Automator

I am running this Applescript in Automator. I get prompted for my admin password as expected but am then seeing an error:

(Error)

Rep argument is not a dictionary

Defaults have not been changed.

My input is either 1 or 2 which I obtain by reading the current default for the domain specified.

(/bin/bash)

defaults read /Library/Preferences/com.apple.alf globalstate

(Applescript)

Generates the error after I login with admin account. Which implies that the problem is with the command. However the same command (in quotes) works when I enter it using the terminal.

on run {input, parameters}

if input = 1 then

do shell script "sudo defaults write /Library/Preferences/com.apple.alf 2" with administrator privileges

else

do shell script "sudo defaults write /Library/Preferences/com.apple.alf 1" with administrator privileges

end if

end run