valet 561r, wire for rear defroster

On that particular vehicle, if you turn the rear defrost on, then turn the key off..  Then turn the key back on, is the defrost on or off?  Does your remote start unit have any outputs that can be programmed for a latched output?  Some vehicles now use data between the defrost switch and the climate control module.  Some of those vehicles you will either have to use a relay tied across the 2 contacts of the defrost switch to mimmick you pushing the button.  Or using a relay to apply 12 volts to the actual wire that powers the grid on the window.  Without knowing what vehice you have really makes it hard to help you.

You could diode isolate the output of the status out wire if of course the defroster turn on is a low current negative trigger, if not you could wire in a relay to boost the signal of the status out!

Again as mr.Idiot said, Year make and model, please!