Marine Air question

mike4110

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Oct 26, 2012
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Hello everyone! I have a 97 Silverton 352 my wife and I recently purchased. While doing the survey everything with the forward A/C was working (heat). when we got it home it was warm in the saloon so we turned on the (cool) side of the ac. after a few minutes i noticed there wasn't too much air moving through the vents. I opened the return vent to gain access to the unit. the fan motor was pretty hot. Not scolding, but hot.

My question is - bad motor? any advice on things to check.

P.S. yes i did turn the fan speed all the way up lol

thank you Mike
 

alldodge

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Hello everyone! I have a 97 Silverton 352 my wife and I recently purchased. While doing the survey everything with the forward A/C was working (heat). when we got it home it was warm in the saloon so we turned on the (cool) side of the ac. after a few minutes i noticed there wasn't too much air moving through the vents. I opened the return vent to gain access to the unit. the fan motor was pretty hot. Not scolding, but hot.

My question is - bad motor? any advice on things to check.

P.S. yes i did turn the fan speed all the way up lol

thank you Mike

:welcome: to iboats

This is a good size boat, and you said when your got it home. I take it you drove the boat home and it was not on a trailer, right?

If the vent was clean and there was little restriction then it may need a motor, The fan should move enough air for the system and the same air should keep the motor cool. Was the fan spinning fast and getting hot or slow?
 

smokeonthewater

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Check it again after it has been off... Iced up maybe?

Assuming you have it in the water.... Marine a/c doesn't work without water.
 

mike4110

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smoke and dodge, thank you for the replies. even if it is froze up. wouldn't it still blow air? cold or hot? The boat is in the water
 
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alldodge

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smoke and dodge, thank you for the replies. even if it is froze up. wouldn't it still blow air? cold or hot? The boat is in the water

Yes it would, I was asking if the fan was turn fast and not moving air or was the fan turning slow?
 

mike4110

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well I am going to check it out this weekend. i will post my findings. Thank you guys very much!!!
 

smokeonthewater

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no if the evaporator was iced over that would stop air from flowing through it.... Can happen pretty quickly in high humidity when freon charge is low....
 

mike4110

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Ok Smoke. So i looked into the slow moving air. I think you might be rite about it freezing over. It was warmer this weekend and needed the A/C while working in the saloon. air slowed a little bit but no where near the first time. Maybe the water is still too cold. Guess i will wait till summer. Thank You
 

alldodge

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Ok Smoke. So i looked into the slow moving air. I think you might be rite about it freezing over. It was warmer this weekend and needed the A/C while working in the saloon. air slowed a little bit but no where near the first time. Maybe the water is still too cold. Guess i will wait till summer. Thank You

The AC won't freeze over the evaporator coil because of water is cold. The colder the water the easier the system will put cold air into the cabin. If the system is low on Freon the evaporator coil will form ice on it. Just trying to find out if your slow air movement is because the evaporator is iced over or because its so clogged up with lint and dirt, or if the fan just won't hardly blow anymore
 

redneck joe

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so not clear - low volume of air or not cold enough air or both? They are separate fixes in my experience.
 

mike4110

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Joe.. so the issue is that when first turned on the air blows pretty strong. after an hour or so i notice that air fades. temp is fine though. thank you
 

redneck joe

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ok temp fine all times just air flow variable. When it slows did you look at the compressor for ice? My guess (only a guess) is a work fan motor if getting hot.
 

smokeonthewater

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Fan motor will get hot if the evaporator ices up because the fan motor is air cooled

O/P as mentioned earlier a dirty evaporator could restrict air flow and cause icing issues... Also under or over charged could cause this....
Water temp is not as likely but could be a factor combined with other issues especially if it is close to freezing.

I have heard of people partially closing the seacock to limit flow in cold water but cannot advise is as safe....

Try setting the thermostat at only a few degrees below ambient so it doesn't run constantly.... Cycling on and off may allow frost on coils to melt away...
 

mike4110

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Update on the fan issue. I ran the A/C for the past few days with no issues and didn't touch a thing. Poseidon must be on my side lol. Thank you all for your comments.
 

ssobol

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I worked on equipment (not a boat) that iced up in high humidity (i.e. summer, when you needed it most). This was due to excessive back pressure in the distribution ducts. Installing a damper that dumped the excess flow reduced the back pressure and the instances of ice build up. Perhaps your fan is oversized or you have some other airflow restriction in your system.
 
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