I have 2 x 9000Btu split aircon installed in my house three days ago. In fan mode it works properly but when I switch to cooling mode the upper pipe from the outside unit freezes immediately, not cold air coming inside, just like in fan mode. The compressor sound running. The other aircon instead of blowing hot air from the outside fan it blows cold. Both aircons have the same problem.
When you says it freezes up, do you mean that you get ice build-up on the pipes and/or condenser? If so, there's nothing you can do yourself. Call an AC tech.