Be sure Battery is Fully ChargedDisconnect Positive Battery CableOpen Drivers Door & LEAVE OpenTurn Ignition to ON Position & leave On.Reconnect Positive Battery Cable.Horn may sound for a few seconds.Start Car.
If this is a Factory Alarm, the Battery is Fully Charged & If the above did not work, then the Alarm Unit is defective & will need to be Repaired or Replaced.
If the Vehicle Theft Security System module is being removed and no replacement module is being installed, the module wiring must be disconnected while the engine is running. Failure to do so will cause a no-start condition.
REMOVAL AND INSTALLATION
Remove upper right instrument panel silencer. Remove glove box assembly. Remove screws (4) attaching mounting bracket to instrument panel. Disconnect wiring. Remove screws (2) attaching module to bracket For Installation, reverse Removal procedure.
Yes, & I am glad you got it fixed. Computers Usually loose their Settings on Removal of Positive Cable, but retain Memory. So when you Removed the negative Cable it erased everything. Hope it works for you.