A/C question

Discussion in 'Electronics Q&A' started by Kathyw, Jul 10, 2018.

  1. Kathyw

    Kathyw New Member

    Jul 9, 2018
    37 sundancer
    8.1 mercruiser brovo 3 axius
    Just purchased a 2010 37 sundancer. Up from a bow rider so we are really newbies! My air conditioner is working fine (cooling and blowing). After turning boat on and off and a very short run (moving dock) i noticed there is no water expelling from side. Is this normal? should this be a constant flow? what happens if you run ac and no water expelling?
  2. bahamabreisus

    bahamabreisus Well-Known Member

    Oct 25, 2007
    Hampstead NC
    500 dancer, previous 420,390,300 dancers
    detriot 8v92
    Your pump should only run when the AC compressor is running. So, if the unit is satisfied with cabin temp where you set it, the pump will not run. Good check would be turn temp down and see if pump comes on.
  3. Riptide III

    Riptide III Active Member

    Dec 8, 2007
    Dartmouth MA
    1997 Sea Ray 400DA
    Cat 3116 TA
    1994 Sea Ray Laguna CC Twin 135 Mercs
    My a/c water cycles on and off. I think it is in synch with the compressor. I would check to see if the pump is running. If it is not, I would then check that the temp is turned down low enough for a cold command. Then I would check the raw water strainer. You don't mention the year or the boat. If it is a late model it might be possible the refrigerant is low and not allowing the compressor to kick on which in turn would not call for water. You also didn't state wether cold air is coming out. This would help.
  4. Kathyw

    Kathyw New Member

    Jul 9, 2018
    37 sundancer
    8.1 mercruiser brovo 3 axius
    It is a 2010 37 sundancer. We have temp set pretty low 65 and it is cold and blowing air fine no messages on the ac thermostat
  5. Stee6043

    Stee6043 Well-Known Member

    Jun 1, 2015
    West Michigan
    1997 Sundancer 400
    7.4L Gassers
    It's worth noting that, depending on your setting, the AC fan is always blowing but the compressor is not always running. If you still feel cool air it may simply be recirculating, not on a cooling cycle.

    The AC system will tell you if it's not getting water when it needs it. Loss of prime is very common and you'll get a message on the display. If you're not getting a message and she's cooling well - have a beer and relax and enjoy your beauty of a Sundancer!
  6. fwebster

    fwebster Well-Known Member TECHNICAL Contributor PLATINUM Sponsor

    Oct 6, 2006
    Middle Tennessee ; Panama City Beach, FL
    1996 450DA
    3116 Caterpillars
    This may help in understanding what is going on:

    The system on 370DA has 2 a/c units and one cooling pump. When one or the other compressor is running, it sends an electrical signal to a trigger inside the pump relay control box.....each uinit has a separate trigger in the relay box. When either or both compressors are running, its/their relay triggers close the pump control relay and the cooling pump runs.

    When the cooling pump does not run for any reason, then the water is not circulating in the cooling coils on the compressor and that will cause the head pressures in the compressor to rise to the cut off point and the compressor will shut itself down. The control panel for the compressor that shuts down will show "Hi-PS" (not "HI-P5") which is telling you the compressor shut down because of high head pressure the cause of which is almost always due to the compressor overheating from low or now water flow.
  7. Little Ducky

    Little Ducky Well-Known Member

    Jun 5, 2017
    Chattanooga TN/Dickson TN
    1998 SeaRay 290 Sundancer
    Twin EFI 5.0L w/Alpha 1 drives
    Obtain an owners manual on your unit.

    It will go through all the function even the hidden features.
  8. dsarge390

    dsarge390 Member

    Sep 6, 2014
    United States
    2011 Sundancer 350
    8.2 Mercruiser 375 w/ Seacore and Axius Bravo III
    The AC only runs on shore power or generator.
    The water will flow only when the Compressor is activated (cycles). It will set a trouble code if there is poor water flow or the refrigerant pressure becomes too high (Lack of flowing water, removing heat from the refrigerant).
    There is a strainer/filter down in the bilge, mounted before the electric water pump. I clean it every weekend. You would be surprised how much muck it picks up in a short time. This pump will turn on and off according to the signal from the control unit activating the compressor. The control unit will cycle the compressor on and off as demand dictates.
    It should be noted that as water temps rise, especially in shallow marinas, the cooling efficiency of the AC unit drops. This is due to the higher water temps being unable to remove heat as efficiently from the coils of refrigerant.
  9. dsarge390

    dsarge390 Member

    Sep 6, 2014
    United States
    2011 Sundancer 350
    8.2 Mercruiser 375 w/ Seacore and Axius Bravo III
    Ducky is right, be sure you have a manual for the unit. I was able to change some settings that made our unit run better. Such as max blower speed and night backlight on the display. It always seemed to be shining right in my eyes.
    Our manual was in a carry case under the flip up backrest in the cabin. Should be cruiseair or something like that.
  10. DougLas

    DougLas Member

    Dec 13, 2008
    Lake Erie
    39 Express
    Check to see if the pump lost prime. If the water does not flow and kicks out the circuit breaker the pump has lost its prime. There are many ways to re prime the pump. The easiest is to make sure the boat is tied secure to the dock, then put the boat in reverse with both motors running. Turn on the air and the pressure from the props will re prime the pump.
  11. LG111

    LG111 Active Member

    Jan 4, 2015
    Now that's creative!!!

    I put a hose to the outlet and run water back through the system. You can hear the air bubbling from under the boat. Primed.
  12. JVM225

    JVM225 Well-Known Member

    Apr 8, 2008
    Farmingdale, NY
    2002 410 Sundancer, Monaco Edition.
    3126 Cats.
    Easiest way I found to prime an AC pump is to remove the hose from the discharge side of the pump for a split second. Just until water comes out of the pump discharge. Then shove the hose back on the pump, tighten clamps, and you’re good to go.
  13. TNT8808

    TNT8808 Active Member PLATINUM Sponsor

    May 25, 2016
    West Michigan
    2008 48 Sundancer
    Cummins QSC 540's
    Avon Seasport 340
    40 HP Yamaha
    +1 as that's exactly what I do!

  14. DougLas

    DougLas Member

    Dec 13, 2008
    Lake Erie
    39 Express
    How is that easier than sitting at the helm having a cocktail while the boat primes the ac. Hmmmm thanks but I will stay with my way the only way I get messy is if i spill my cocktail.
  15. wayne0

    wayne0 Active Member

    May 4, 2014
    Newburyport, Ma.
    2000 340 Sundancer
    Twin 7.4 ltr.V-drives
    As long as it works. If not, I do the hose thing.

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