Steve:

Many thanks for this site…. extraordinarily helpful !  Here is my problem :

Boat : 2003,  38 foot Hunter sail

Unit: Marine Air Vector Compact 16,000btu w/ Passport II control

Location: Lake Erie    98 degrees this past week.  Water temps in the mid to high 70's

The intermittent nature of this problem is driving me nuts.

Sometimes the system will run for 10 minutes and shut down, sometimes it will run normally for 2 days, then decide to shut down. Turning the unit off and restarting will sometimes produce a valid restart with proper cooling, sometimes not.

When I say shut down, this is what happens :  Unit will run for approx 10 minutes and the compressor and pump stop, but the fan continues to run. The A/C light on the Passport II is still lighted. Sometimes the compressor and pump will restart after 5 or 10 minutes, sometimes not. All of this occurs before the temp set point is achieved.

Then, without an apparent reason, the unit will work fine for a day or 2 before exhibiting these symptoms again.

When the compressor is running, the unit cools as well as it did when new. A couple of times, but not always, the compressor will shut down, but the fan AND pump will continue to run.

What I have done:

Cleaned intake strainer and inspected pump impellor.

Ran garden hose water pressure through the coils to clear any debris

Replaced Run Capacitor (that seemed to work once before, but symptoms returned after 3 weeks normal operation)

Tightened all wire conections

Had a Tech check refrigerant levels and pressures. All OK according to him

Water flow out of the overboard discharge appears to be as voluminous, and clean, as ever

Unit is installed under some seating. I removed the entire top of the seat (plywood and cushions) in case restricted air flow was an issue

Coils are not icing up. At least not obviously. Can they ice in an area away from my view ?

Frequently notice clicking coming from, I believe, the reversing valve as the compressor shuts down, but cannot confirm that this happens all of the time. Does the reversing valve operate each time the compressor starts or stops ?

Unit is in cool only mode

I'm hot Steve ! Sell me a part to fix this

Jeff