Hey, I have an old Goodman that had a blown transformer. Change the transformer - now inside unit runs fine but the outside unit will not go into ac mode. I replaced the board with no luck. When I remove the wires and test the reversing valve it reads dead short, but tested another unit and same thing. I removed all wires and plugged the reversing valve to red and black (30 V) and did not hear the famous hissing. I even took a hammer and tapped it.
My question is shouldn’t I hear the hissing just by putting 30V to it? Should it read a dead short. If it is not the reversing valve, what else could it be. When I hook up all wire except the orange it works great but in heat mode.
you may have ruined the valve since you hit it with a hammer.....doesnt matter how hard you hit it. It may stick now. Often the coil that controls the valve can be removed. The noise you expected to hear would not be heard without the unit running.