2004 F-150 crews rear vent heating

By Rick F.

In Canada it gets friggen cold, so why does the rear centre vents only come on with the panle vents on. I can't blow warm air into the back unless I take the air off the defrost. So either I freeze out the kids or I can't see though the windsheild. In my Lariet, there is a button for floor/vent combo or defrost/floor combo. Why can't I have a defrost/vent combo? Can I have something rewired or is there something that I could do?