Options

AC Fan Slowing Down

Hello all, this is our first year with a 2004 270 FV, we love it and all systems seem to work fine and our AC was great until last weekend.  Water is running through it fine, but after a couple of hours running the fan (on Auto or manual fan speeds) slows to a trickle of airflow coming out of the vent, not nearly enough to cool off the cabin.  I have to put my hand right up to the vent to even feel anything coming out.

I checked the intake vent and the filter seems fine, there is a white plastic wall behind that which is very very cold.  I have a feeling maybe the fan is bad?  What is that wall? Except once it's been off for a few hours it will run ok again until it slows down again like before.  Anyone had this problem or know what to check?  Is there a way to blow a fan through there to see if that's the problem?

Thanks ahead of time!

B) 2004 270 Fiesta Vee - Bull Shoals Lake, AR - 350 Mag Bravo 3

Named her "FAMILY THERAPY" 

Best Answers

  • Options
    Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭
    Answer ✓
    The unit is freezing up, so zero air flo. You can adjust the programming to prevent this. There are several threads on here about that or look up your controller instructions. For short term: turn it off to melt. :)

    Past owner of a 2003 342FV
    PC BYC, Holland, MI

Answers

  • Options
    270FVFamily270FVFamily Member Posts: 20 ✭✭
    Thanks Raybo, I think you're right, whatever that wall is behind the air return seems like a solid wall of ice.  I suspect it may be freezing up because the fan is slowing down so much. Or, is it slowing down bc the unit is freezing up and no air can get through?   

    B) 2004 270 Fiesta Vee - Bull Shoals Lake, AR - 350 Mag Bravo 3

    Named her "FAMILY THERAPY" 

  • Options
    BruceBruce Member Posts: 167 ✭✭
    If the unit is indeed freezing, that can be cause from low airflow past the evaporator, which is usually the result of a dirty/clogged air filter or a dirty/clogged evaporator itself. If that is not the case (as strage as this may sound) it can be caused by the system being low on freon.
      Hope this helps, and good luck.
    2004 250 FV 
  • Options
    TikiHut2TikiHut2 Member Posts: 1,431 ✭✭✭✭✭
    I found the return air duct laying loose in the bilge under our aft bunk. If it's low air flow it may need to be re-taped back onto the register or even at the a/c unit. As you can imagine, it made a world of difference in the cabin rather than just cooling the bilge bugs.

    Mike
    2004 FV270, 300hp 5.7 350mag MPI Merc 305hrs, 2:20 Bravo3 OD w.22p props, 12v Lenco tabs, Kohler 5kw genset, A/C, etc.etc...
    Regular weekender, Trailer stored indoors, M/V TikiHut, Sarasota, Fl
  • Options
    BabyboomerBabyboomer Member Posts: 918 mod
    edited May 2014
    My fan went bad a few years back was made in Italy took 2 weeks to get it easy fix just the wait went through a Local Marine AC guy to order had to pull the fan and give all numbers on the unit. Also the filter is on the inside f the unit like looking at it it' facing the hull. Now I duct tape a regular furnace filter to the inside of the return grate wall that grate is screwed to is easily removed.


    Slip 866 Sunset Marina Byrdstown Tn
  • Options
    270FVFamily270FVFamily Member Posts: 20 ✭✭

    Hello all and thank you for your answers. After messing with this a bit it is absolute that the cold white wall behind the intake vent is indeed the evaporator (looks like a radiator?), with no airflow it had turned to solid ice!

    I'm going to guess it's not too low on freon? Where I'm at is a beautiful clear lake, and no Marine AC guys at all. Matter of fact we're one of the few cruisers on the lake at all, the only boats bigger than us are houseboats, lol.  Here's our newest cove:

    LOVE OUR RINKER!

    Anyway, I'm handy but kinda on my own to diagnose and no tools of the trade so to speak.

    However, I believe Babyboomer may be onto something with the bad fan.  Works like a champ at first, for about an hour or two.  I'm guessing again, that the fan is slowing down after it gets heated up for awhile and the evaporator freezes, making it even worse.  With the summer heat coming on I'd like to figure it out. I've got a small electric fan that fits perfect in front of the intake vent, so I'm just going to turn it on next and see what happens.  That should at least tell me if its a fan issue?

     

     

     

    B) 2004 270 Fiesta Vee - Bull Shoals Lake, AR - 350 Mag Bravo 3

    Named her "FAMILY THERAPY" 

  • Options
    270FVFamily270FVFamily Member Posts: 20 ✭✭
    Yes RinkerYan, when first switched on it blows plenty of nice cool air into the cabin, there's only one outlet vent under the stairs.

    B) 2004 270 Fiesta Vee - Bull Shoals Lake, AR - 350 Mag Bravo 3

    Named her "FAMILY THERAPY" 

  • Options
    WeberWeber Member Posts: 249 ✭✭✭
    Try just running the fan for an hour, with the ac off.  This will tell you if the blower is going of on overload, going bad in general, or if there is another problem.

    If the fan continues to run just fine, then you have an airflow problem or refrigerant problem.

    Check your filter and your return duct.
    Sin or Swim - Rinker 312
  • Options
    270FVFamily270FVFamily Member Posts: 20 ✭✭

    Didn't try just the fan Weber, although I should, that's a good diagnostic idea.  For the 4th our family of 5 stayed on the boat 5 days and I had just hooked up a small 10" square box fan in front of the intake vent and the AC ran all night just fine.  I have a feeling I'll be replacing the fan unit.

    We watched 3 different fireworks shows in different cities on the lake each night, never watched those on the water before, was really cool. 90 miles we traveled!

     

     

     

     

    B) 2004 270 Fiesta Vee - Bull Shoals Lake, AR - 350 Mag Bravo 3

    Named her "FAMILY THERAPY" 

  • Options
    raybo3raybo3 Administrator Posts: 5,468 admin

    That is awesome. I love seeing the fireworks from the boat.........
    2002 342 Fiesta Vee PC Point Of Pines YC Revere MA. popyc.org     raybo3@live.com
  • Options
    270FVFamily270FVFamily Member Posts: 20 ✭✭
    I know this is an old thread but just thought I'd update in case anyone else ran into this, the problem with the AC unit freezing up was as simple as I had it turned down too cold.  I had it the temp down as far as it would go and the unit wouldn't get the chance to cycle.  Basically it just has to shut off for a bit to warm the condenser a little.  I keep it on 73 or 74 now, the cabin is really comfortable and the unit runs when it should.  This was my first boat with AC and I'm guessing was just a newbie thing. Yay

    B) 2004 270 Fiesta Vee - Bull Shoals Lake, AR - 350 Mag Bravo 3

    Named her "FAMILY THERAPY" 

  • Options
    rasburyrasbury Member Posts: 8,282 ✭✭✭✭✭
    Hey, it's always a nice surprise to find it's something simple....
  • Options
    DanD2DanD2 Member Posts: 847 ✭✭✭
    Humidity plays a huge role here. The more humid it is, the bigger chance of things icing up.
    No longer a boat owner.....previous boat - 2005 Rinker Fiesta Vee 342
  • Options
    Dream_InnDream_Inn Member, Moderator Posts: 7,589 mod
    You can also set it so it reverse cycles once an hour for whatever duration you set.  then you can set it at 65 and not worry.

    Dream 'Inn III -- 2008 400 Express

Sign In or Register to comment.