You need to get the water out, before the internals rot.
Since they are suposed to be sealed... the only way to do it, is to drill a hole (or 2) and dry them out. I've done it 2 ways. If the wires in the back can unplug... drill one hole in the black case, and blow dry air in. (like from those dusting cans) That will push the moisture out. Then put a dab of black RTV over the hole. If it doesn't unplug... drill one hole toward the front, and one toward the back so you get a flow of air.
Don't blow too hard... you don't want to break anything. Also, you don't want to use shop air, because it will be VERY wet. IF... you have an TIG or gas MIG welder... using pure argon is a great way to do it. It's EXTRA dry, and it will displace the O2, and keep the internals healthy longer.
