Not water flow on ac units 1996 355

[Drspikes355]

Hey folks, I would appreciate any ideas on pump failure to run all of a sudden on recent startup.
I’ve been using one or both units through out the winter for heat an recent ac use. This past weekend wasn’t particularly hot but wanted to cool down the cabin so i turned on the unit and it came on blew air , but when I checked I had no water flow so I shut it off and tried the secondary unit to see if it was a control issue of some type. Same - no water flow so shut it down.

I don’t recall any messages on screen just blowing warm air.
The strainer is okay but the motor didn’t seem to run at all.

Is there a separate fuse or anything I can check as the circuit breakers were not blown and I switched them off and on to make sure. I applied any ideas as it’s hard to find an ac- mechanic to come and check. Thanks much.

[g36]

In the electrical panel there's a ac pump breaker which should be on. . in the bilge You'll have a pump relay box also but If you have access to a volt meter it would be very easy to check voltage at the ac water pump. If it's got power but the pump isn't on then you'll know right away the water pump is defective.

[Drspikes355]

Thank you so much.
The breaker was on and I reset it but I will try to get to the pump and check to see if there is power.
I’ll look to see I can identify the relay. I’ll report back when I get further.

[g36]

Check pump voltage first very easy. Voltage there then bad pump, If no voltage when ac units are on then you may have to go to check here also. The relay box is a white metal box and will look very similar to this link. This brand won't neccesarily be the brand/model you have but it will help you identify what your looking for. It allows 2 or more air conditioners to use a single water pump allowing each turn it on independently instead of having multiple water pumps........https://wateryachtsolutions.com/pr3x-pu ... -triggers/

[Viper]

See if your control box is on the aft bulkhead in the compartment under the dinette table.

[Drspikes355]

Thank you for the information. I’ll get over this weekend and see if that’s the issue. Appreciate all the help and knowledge.

[Drspikes355]

If the relay is bad is it evident by discoloration or burnt look ? I hope to check it out this weekend. Thanks again.

[g36]

No the the outside of a relay will generally appear fine you would (if its a 2 piece type case) be able to pop it open and possibly see burnt contacts that would indicate an issue. But a relay can fail with the coil or contacts being a problem. Theres ways to check relays with a meter also. There will be a circuit board there also which could also have a issue. The main thing with this is to see where the power to turn the pump on is being lost.
The relay box will be 110v so if you do open the cover do it with power off first then energize the ac system and carefullly measure line power coming in the output going to the pump.. this isn't difficult but you should be comfortable doing this or get a tech to look at it. I don't want any person to do something they aren't comfortable with.

[Viper]

It might be but not necessarily.

Did you check to see if the pump is actually running or not? Don't just go by no water over the side, the motor might have power but could be seized or it could be running but the impeller might have failed. It may also have lost its prime for some reason and needs to be primed. They can be pretty quite and hard to tell if they're running sometimes. If it's seized, you should hear a hum or you should feel some heat when you put your hand on it after it's been powered up for a while. If it's running but not pumping, you should also feel that when you place your hand on the pump. Get yourself a non-contact voltage probe and check the wire at the pump, if it lights up you have voltage there. You should have one of these on board anyway. Make sure an A/C unit is turned on and the pump power is turned on. These are easy checks before getting into the control box.

[Drspikes355]

I believe the pump is not running at all as with center hatch open I heard nothing.I will have to get the couch out of the way to get the other hatches open. All very helpful information if I feel it’s beyond my level at least I can inform a mechanic what’s been done so far. I will post what I find out. Thanks again.