I believe that if all is working correctly, the idle should come up a bit when the rear defroster, lights, etc are turned on. The computer should be adjusting the idle to compensate for the alternator drag. At least mine does. 
- Jim
Our yardbirds:
Belvedere, our '96 Jeep Cherokee, 4.0L ATX, 85,000 and going strong
Spencer, our '03 Chrysler PT Crusier, 2.4L ATX, 28,000 and just getting started
| 
