O.K., I have no doubt you hooked up the wires as described, BUT how do you switch between A/C and Heat pump? Also, when you say the A/C and heat are on at the same time, you aren't talking about the furnace heat, are you?
The A/C can't be both in cool and heat mode at the same time. If the A/C is on cooling, the heat must be from an electric 'emergency' heat grid in the A/C duct.
How did you turn on the electric heat grid in the previous set up?
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI