I am replacing a honeywell 7400 with a honeywell TH8320. I do have a heat pump. I need wiring help.

The existing 7400 terminals that are used are C,G,Y,OB,R,AUX and E
C-blue wire
G-green wire
Y-yellow wire
OB-orange wire
R-red wire RC (R,RC jumped )
AUX-white wire
E-black wire

The new thermostat terminals are Y2,L,E,AUX,S1,S2,RC,R (R,RC jumped), OB,Y,G and C

Could you show me the wiring setup for the 8320. Thank You for your time.

From what I've been able to dig up it looks like you wire it up the same and ignore the others. The ones to ignore are as follows:
Y2 - second stage compressor
L - reset
S1, S2 remote sensor

Write down all the function setting on your 7400 so you can configure your 8320 the same way. Some HPs have the reversing valve energized opposite of the tstat or vice-versa.

I did wire it the same and I have no AC

What are your setting for functions 170 and 190? Do they and all other settings match your 7400?

Remember that R and RC jumped become R. If Rc is missing, you won't have cooling.

The VP series is a difficult install because of all the configuration options.

170 - 2 heat and 1 cool

A question about function 190 Do I want the OB to control the valve in cooling or heating

R and RC are jumped

I have been installing the 8320 where I work and have not had any problem at all. I have been replacing 4 different types of stats. When I changed my home stat things started going crazy.

170 - 2 heat and 1 cool

170 sounds looks correct. I assume you mean that's set to value 7?

a question about function 190 Do I want the OB to control the valve in cooling or heating
What does your heat pump expect, or what was the 7400 set to? Some HPs energize the reversing valve different for heat or cool.