A quick reference to determine if a 124 vehicle is fitted with convenience feature is to look at the door handles, the chrome strips are a dead give away. You did say that your windows do work with the one touch "Down" command via the switch group. This may be a good sign because the control unit is responding to the “Down” command. Have you tried operating the "Convenience Control” from either the passenger door or the trunk lock? If not, try it at the other two points and let us know what the results are.