It sounds like the revering valve is the opposite polarity then what the thermostat is providing.

Are you replacing an old thermostat with the Trane 803? If yes, then you need to connect the wires by the terminal names used by the old thermostat (W, R, G, etc,) and not by wire color. Hopefully you remember how the wires were connected.

Did you go into the installer menu and and select the correct system type selection for your heat pump? I think it is installer setup number 0170.

Thanks Mike, I think you nailed it.I misplaced the manual when I moved but found instructions online since my post.At your suggestion I followed the instructions and got it set at 0170 1 but don't have a clue what to do next. My other thermo was very basic What should I do next ?

You should go to control board in the air handle and figure out what wire is connected to what terminal. I found the service instructions for a Goodman heat pump, but I am not sure if it is your model. Look at page 60 to see what the control board terminals look like on the thermostat side.

You want to find out the color wire is connected to the "O" terminal. This controls the reversing valve. Determine the other wires also. You may have other mistakes.

I am not a heat pump expert, but I think the Goodman heat pump needs the O terminal energized (24 volts) in cooling mode. I think the blue wire needs to be moved from the B terminal to the O terminal.

I recommend establishing the wire/terminal connections before you start moving wires.

Here is a link that might be useful: Goodman heat pump manual

Mike, this house built in 97 and originally had a 2.5 ton Carrier HP but the owner had enclosed the attached two car garage which made the unit undersized.I'm going to enclose the lanai which will make the situation even worse so I replaced it with a Goodman 3.5 ton hp. precharged unit which I installed it myself and saved $2000 over lowest estimate. I had this new T803 that was given to for doing some electrical work and thought I would try it.I just installed the old carrier thermo which I was familiar with and the ac is up and cooling great. I don't really need the T803 so I might just sale it.Anyway thanks again for your help.