[honest mark]

i have a 2003 4200 open, when i turn the ac on in the bedroom it cools the bedroom perfectly, however if i turn the ac on in the galley area AND in the bedroom at the same time  it doesnt blow as hard or as cool in the bedroom?? i did clean out the bottom vent in the bedroom which was quite dirty, is there a strainer or anything down in the engine room for the ac that needs to be cleaned?need a little help, thank you.