1986 monte carlo ss computer problem

[kitsapchopper]

my check engine lite stays on even if i disconnect the computer.if i plug in the scanner it says computer is not responding..this is driving me me nuts ,any ideas ?? i know there is power to the lite at all times and it does not come on untill the lite is grounded,thru the scan port or the computer enables it .maybe i am wrong but someone should be able to tell me more i am sure .