Hi All - 1997 370 Sundancer ...

[CKboater]

Hi All - 1997    370 Sundancer   Had it for 20yrs, all of a sudden the air conditioning cooling is loosing is prime, only after a cruise.  Calm waters or not so much, still loosing its prime.  From the inlet to the sea strainer is only 12" long hose, if that and I see no water leakage, although I shouldn't since its air getting in.   The intake has a South Shore sea strainer on the bottom.

Any Ideas where to start looking.   

[wingless]

Didn't locate a South Shore sea strainer.

My boat was built w/ the Groco STH scoup through hull. IMO, these are horrible, permitting interior marine growth that is virtually impossible to remove, even when on the hard, picking away through the slots.

https://www.groco.net/products/fittings/scoop-thru-hull-fittings/sth-series-scoop

My boat has been changed to using the Groco APHS strainers w/ standard mushroom through hulls. These are infinitely better. I have almost no interior growth, from one the hard service to the next, easily cleaned when applying new paint. My APHS strainers were properly bonded using a long bolt to a green bonding wire.

https://www.groco.net/products/raw-water-strainers/hull-strainer/aphs-series

It is possible that marine growth is obstructing the free flow of water.

It is likely that hoses have deteriorated and have small leaks. My guess would be on the suction side, from the pump to the strainer to the through hull, based on the symptoms.

[CKboater]

My bad - there called "South Bay Sea Strainer" by Buck Algonguin. I don't think its the hose, as I do not run the A/c while the boat is running, Also, it can sit all week with the dehumidifier mode on and it will not loose the prime. Only looses the prime after having moved the boat. I tried attaching a picture of the strainer.

[wingless]

The image didn't work.

If prime is being lost, then the problem must be on the suction side of the pump. It must either be a leak or an obstruction, or both.

Another looong stretch possibility is that the raw water pickup is incorrectly located, or obstructed by other underwater hull objects.

[CKboater]

OK Thanks - I'll replace the inlet hoses from seacock to stainer and from strainer to pump.