I have a new honeywell rth6350 and a trane heat pump. I have an older 8 wire system and trying to wire a 5 wire therostat... I know the black wire is open at the pump. I can't get the system to even turn on. What wm I doing wrong...

The most common set up is:
Red wire to R on stat
Green wire G on stat
White wire to W
Yellow wire to Y
Orange wire to O
Send some pics of wire coming out of the wall and terminal strip in furnace.