Common problem with the water seals apparently. Take ur lights off and check the rubber seals between the cluster and the bulb holder.
Make sure its all straight and the groove in the center of the rubber is in the middle throughout.
Also inspect the clusters, if there are any cracks in them there might be water leaking through from there.
Buy some electrical contact cleaner and clean everything out, u need to make sure theres no water left on the inside that could damage any of the components on the bulb holder.