370 Express Cruiser A/C cycling between heat and cold.

[hmrjason]

I have a 370 express cruiser with 2 cruisair conditioning systems. The aft A/C will come on when temp is set an cool button is pressed. I am getting good water flow but it keeps turning off and switching to heat for 30 seconds or so then switches back to cold. The cold light display on my SMX II controller never goes off. Does anyone have any idea would could cause this? Any help would be appreciated.

 

[RaySea Girl 2]

Sounds like a thermostat or control board issue (on Cruisair systems I believe that they are integrated - t-stat and control). Depending on your level of mechanical and technical diagnostic ability you may try switching the front contol with the rear, if it does not cause any damage to either unit or the mounting areas. Marine a/c and heat units are essentially heat pumps and the flow of refrigerant is just reversed via a switchover valve when the t- stat calls for heat or cool. Also check connections for corrosion or looseness at the control and at the unit.
Ray

 

[hmrjason]

Great Idea. I will try that today and see what happens. Thanks for your help.

 

[electricaldoctor]

Your thermostat may be stuck in a diagnostics mode. Re-check your programming.