We purchased our 1990 310 Sundancer around Labor Day last year, and it is Great (mostly). The A/C unit coninually has been freezing up after running for 10 to 12 hours. While running it blows cold and we have no issues, until the find for the coils freeze up. Had a few opinions from friends, but wanted a better source. The intake vent/filter comes from the main cabin under the front V-berth. The A/C unit is located under the V-berth, and the coils are on the side of the unit closest to the bow. My thought is that the unit was installed backwards and that the coils should be facing the vent opening (towards the main cabin). It seems to me that the return air needs to come from the main cabin, through the vent/filter, around the entire unit, and then reach the fins/coils. I have checked the water filter basket and the air filter in the cabin ... all clean there. Any thoughts on what the proper orientation of the A/C unit should be ?