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AC water pump location.
Posted: May 13th, 2025, 4:48 pm
by MQtdavid
I have a new to me 1985 3697 Mariner. I’d like to run the AC but it doesn’t seem like the AC water pump (assuming one pump for both AC units) is moving water in either forward or aft AC. Problem is I do not know where it’s located. I’ve found the water pump for the general water. But that’s not the AC water pump. Any help would be appreciated.
Re: AC water pump location.
Posted: May 13th, 2025, 5:07 pm
by km1125
If you haven't primed it, then maybe that's all that it needs. I'm not sure exactly on that model, but I'd suggest just forward of the engines is a likely spot.
But even if you got it primed, you should still know where it is, along with the strainer and seacock.
You also might have the thru-hull seacock closed.
Re: AC water pump location.
Posted: May 13th, 2025, 7:32 pm
by waybomb
In the galley. Under the floor. There's hatch there. Unscrew the to of the strainer until water leaks out. Tighten it back down.
Should work
You should lift every hatch and familiarize where everything is located.
Under the bed.
On the floor at the foot of the bed
On the galley.
Centerline next to the galley.
In front of the steps.
Under the table.
Next to the port seating.
Under the cushion to the starboard side of the main door.
And of course the thre in the cockpit
Re: AC water pump location.
Posted: May 13th, 2025, 10:00 pm
by buster53
waybomb wrote:Source of the post In the galley. Before the floor. There's hatch there. Unscrew the to of the strainer until water leaks out. Tighten it back down.
Should work
You should lift every hatch and familiarize where everything is located.
Under the bed.
On the floor at the foot of the bed
On the galley.
Centerline next to the galley.
In front of the steps.
Under the table.
Next to the port seating.
Under the cushion to the starboard side of the main door.
And of course the thre in the cockpit
Totally agree with waybomb. You should know the location of every through hull and what it feeds, all strainers, all bilge pumps and sump pumps. You should be able to look at any hose and know immediately its purpose and where each end is located.
Most likely, your AC water pump can be found in the engine room as well as the strainer and through hull that feeds it, and yes, it feeds both AC units. Make sure the sea cock is open and as mentioned it could simply be an airlock in the hose and “burping” the strainer is usually enough to clear the airlock.
Re: AC water pump location.
Posted: May 14th, 2025, 8:40 am
by waybomb
My 3697 has the strainer and pump below the galley floor
Re: AC water pump location.
Posted: May 14th, 2025, 8:51 am
by Midnightsun
I am lucky as my AC pump does prime on it's own after it is put in the water. That being said my previous boat did not. Only found out after years of use that if one runs up on plane it self primes due to the pressure and is good for the rest of the season. Not saying all boats do this but worth a try upon spring commission as sometimes priming these can be a real PITA.
If it's not priming on it's own, then the installation is less than ideal. Reason is, if the pump is lower than the water line it will always self prime.
Re: AC water pump location.
Posted: May 14th, 2025, 10:08 am
by bud37
Midnightsun wrote:Source of the post If it's not priming on it's own, then the installation is less than ideal. Reason is, if the pump is lower than the water line it will always self prime.
We had the pump lower than the waterline on one boat and it always needed help to prime after being out of the water like for instance, going over the marine railway ......I put it down to the strainer along with the pump impeller design, also the hose routing, running fast would generally fix that by creating some suction pressure.
Re: AC water pump location.
Posted: May 17th, 2025, 4:20 pm
by buster53
MQtdavid wrote:Source of the post I have a new to me <a href="tel:1985 3697">1985 3697</a> Mariner. I’d like to run the AC but it doesn’t seem like the AC water pump (assuming one pump for both AC units) is moving water in either forward or aft AC. Problem is I do not know where it’s located. I’ve found the water pump for the general water. But that’s not the AC water pump. Any help would be appreciated.
Have you found the pump yet and was it the problem?