Hi PS on Old Cruisair

[R1Guy]

Having an issue and wanted to get some thoughts before I call in some maintenance help.


I have two AC systems, one in the salon and one in the aft cabin. I was told by a previous maintenance guy that there is one sea water pump that services both condensers. I am now getting a Hi PS reading on my panel in the aft cabin, the salon is working fine. When the salon AC runs, I can see water flowing out of the thru hull as it should. When the aft AC runs, however there is no water flowing. I tried running the system in heat pump mode to see if that would clear it up, no flow. As the salon ac is working fine, I cant see that this would be a sea water pump problem or sea strainer.


What else could be causing no flow when aft ac is running? Just wanted to see if this was something I might be able to troubleshoot or if this sounds like something that id need an expert for in the unit itself.


Thanks.
Dan

[R1Guy]

Nevermind, I did some more testing and searching in the bilge. I checked down below and there is indeed one sea water pump servicing both ACs. Also, there are two water discharges, port and starboard. I had thought one was for salon ac and one was for aft ac and I looked at how the discharges are piped, and each comes directly of one of the condensers as you would expect. However, when I run the Salon AC, I am seeing water discharge out of both port and starboard telling me there is water flow through both the Salon the Aft AC even if the Aft AC is off. So, no clog in the Aft AC. At this point, it seems that when the Aft AC goes into heat or cool mode it is not turning the sea water pump on as there is no flow. When both are on, no HI PS so it seems that since the salon ac turned the pump on, the aft ac is happy.


Sooooo, time to call for help!


Dan

[transmitterdan]

Originally Posted by R1Guy

Nevermind, I did some more testing and searching in the bilge. I checked down below and there is indeed one sea water pump servicing both ACs. Also, there are two water discharges, port and starboard. I had thought one was for salon ac and one was for aft ac and I looked at how the discharges are piped, and each comes directly of one of the condensers as you would expect. However, when I run the Salon AC, I am seeing water discharge out of both port and starboard telling me there is water flow through both the Salon the Aft AC even if the Aft AC is off. So, no clog in the Aft AC. At this point, it seems that when the Aft AC goes into heat or cool mode it is not turning the sea water pump on as there is no flow. When both are on, no HI PS so it seems that since the salon ac turned the pump on, the aft ac is happy.


Sooooo, time to call for help!


Dan

Dan.

There is a box somewhere down below that controls the sea water pump. Both air con units connect to this box. Inside the box are at least 2 relays. Most likely one of these relays is defective and not turning on the sea water pump when that air con unit is operating. It may be as simple as tapping on the relay to get it moving again or replacing it. You might need to know how to use a volt meter to troubleshoot a stuck relay.

Be careful because inside that box there is live 120V AC. If you don't feel comfortable working around live 120V AC then by all means call in an electrician.

[R1Guy]

Originally Posted by transmitterdan

Dan.

There is a box somewhere down below that controls the sea water pump. Both air con units connect to this box. Inside the box are at least 2 relays. Most likely one of these relays is defective and not turning on the sea water pump when that air con unit is operating. It may be as simple as tapping on the relay to get it moving again or replacing it. You might need to know how to use a volt meter to troubleshoot a stuck relay.

Be careful because inside that box there is live 120V AC. If you don't feel comfortable working around live 120V AC then by all means call in an electrician.

I didn't realize that. Thanks for that feedback. I may try to see if I can track down that relay box tomorrow. I can at least give the relay a tap or two to see if that frees it.

[transmitterdan]

Originally Posted by R1Guy

I didn't realize that. Thanks for that feedback. I may try to see if I can track down that relay box tomorrow. I can at least give the relay a tap or two to see if that frees it.

It’s possible there are some fuses inside that box too.

[transmitterdan]

It’s also possible there is a water pump fuse inside the air con control box at the compressor unit. It usually has 4 screws to remove the cover.

[R1Guy]

Originally Posted by transmitterdan

It’s also possible there is a water pump fuse inside the air con control box at the compressor unit. It usually has 4 screws to remove the cover.

So got down into the bilge tonight and found the pump relay box. However, there is alot in there and frankly I dont know what im looking at. No fuses in there.


Found the condenser control box and popped off the top. There was a wiring schematic in there. No fuses shown on the schematic and the screws to get the rest of it open are in very rough positions.


So, while I like trying to figure things out in this instance I think Im going to get a professional in and maybe hang around and watch what he does to learn.


While I was down there, definitely confirmed that pump does not go on when the condenser activates like it should. So either something wrong in the control box, or in that pump relay box.


Thanks for your help.