- The switching is done electronically via microprocessors, rather than mechanically.
- There is no practical way to alter the circuit board to disconnect the A/C and defroster.
- The only way to do this is to install a switch to manually turn off the A/C when you don't want it to come on with the defroster.
- A switch is spliced into the #17 wire in the connector for the heater control module. (yellow with black stripe)




- The best switch setup I could come up with requires sacrificing the cigarette lighter to provide a convenient and sensible location for the switch.
- The finished setup looks like it belongs there.



- The bypass switch works perfectly. When the switch is turned off, the A/C turns off, whether it was activated automatically by the defroster or manually with the A/C switch. The defroster continues to work normally otherwise. If the switch is turned back on, the A/C comes back on.
- The A/C switch light is independent of the operation of the defroster and the bypass switch. If the bypass switch is turned off and you press the A/C button, the light comes on, but the A/C does not.

http://www.elantraclub.com/forum/index.php?showtopic=4393

More photos can be found here, compliments of BNystorm: http://rides.webshots.com/album/464134161SnluyZ