2004 Grand Prix Rear Defroster

I have a Viper 791xv that I installed in my 2004 Grand Prix a few months ago.  I didn't hook up the rear defroster at the time and would like to now.  Has anybody hooked up the defroster on one of these or does anybody know which wire I should use?  Thanks.

take out the climate control panel and look on the back of it. test for any wire that goes (+) or (-) 12 volts when you push the defroster button. its either (+) (-) or pulsing (read pulsing, not one pulse). if its pulsing call DEI. otherwise use a relay to supply the proper trigger to the wire you find and use the same value fuse as the factory defroster fuse. unless you put a toggle switch the defogger will turn on with every remote start for the first 10min. so use a switch to break the signal during the summer or whenever there is no snow. hell, just use ch4 and program it to latched or pulse whatever you need. then remote start and then hit ch4.MECP certified installer

Thanks for the replies.  I did some checking during my lunch break today and it is pretty much the same as the 97.  It's still controlled by a white wire that goes to ground.  The only difference is the location.  The relay for the defroster is on the back of the fuse block on the passenger side.  The wires are in a junction block type thing at the bottom of the fuse block.  Thanks again.