Need some help on a 1997 Chocho package rooftop unit. Customer wants new stat,but i can't identify any of the contol wiring at stat. It has a Trane programable one that I'm not up on. It's got several wires on a numbered cicuit board. Does any body have a wiring schematic. Thanks,,, The model of unit is TCD075 with electric heat. It's wired now with a auto change over stat..