Your capacitors are good as it heats and the fan blows. On that vintage units, they default to Heat when there is not power to the reversing valve. You have done everything possible other than tapping on the valve in the hopes you can help it reverse to cooling... your last resort before replacing the entire unit.
Unfortunately it is not a simple put a new unit on the roof because the new units default to cooling when there is not any power to the reversing coil. There is a kit that you will need to make it work with your current Tstat. PM Doug Rainer for info on this kit.
