CruisAir AC intermittent cold to warm

[Cwalther1]

This weekend, my ac started off blowing cold, took the hot boat down from 95 to 80 in less than an hour. After a while, I noticed that it was not blowing cold any longer and the temp started to raise to 85-89. Then 15 minutes later, it started cooling again, down to 75. This process continued all day, then at night, it would finally get down to 72 and maintain at that temperature. Next morning, it stayed around 72 until about 1pm, then it started doing blowing cool/warm air again. This is new, as it has been able to keep up all summer. Will cool fine for 20-30 minutes, then blow cool/warm for 20-30 minutes. Strainer has been cleaned, filters have been cleaned. Not sure if it's freezing up, but I never received any P5 or L5 pressure errors, and the units never shutdown. This is a single pump, 2 cooling units setup. The 2nd unit in the vberth cooled all weekend just fine. It is the unit in the salon that is acting up.

just trying to determine next steps:

check freon
check for bad high pressure switch
check for dirty intake vents/vanes

what could be causing this cyclical behavior.

Any help appreciated.

Riviera 2001 Flybridge 43'

Charlie Walther

[Turtle Blues]

Usual suspects in order;
Your #3 first, clean filter, clean coil, verify unobstructed airflow.
If none of the above couple of checks before suspecting freon issue;
What parts are operating when unit is blowing unconditioned air? Fan only, compressor intermittently or not at all?
What are the temperatures of the supply and return air under this condition? Is it just unconditioned (ambient temp) or actually warm?