A/c "clunk"

[Bill Root]

I turned the aft deck AC on for the first time yesterday. The unit blew cold air, but cycled on and off every few seconds and went "clunk" every time the compressor cycled. Is the compressor dead? I have an AC guy coming next week, but would like to have some intelligent questions to ask before he tells me to throw it out and put in a new one.

Thanks

 

[Robby]

Figured you were on the 54.Check your pms.Robby

 

[bigbill]

do you have overboard discharge water? sounds like it may have high head pressure.

 

[fissioneng]

Sounds like a bad start capacitor. If so, easy and inexpensive to fix.

 

[Boatsb]

sounds like short cycling. Low pressure shuts it down. If it is temp it usually takes longer to restart.

 

[Bill Root]

Thanks, everyone. You have given me some good information to use with tghe AC repairman. I hope you are all correct and this is will prove to be a relatively minor problem. I was getting prepared for a new compressor.

 

[Boatsb]

they will shut off with high pressure too and that may be what is triggering it. Just a thought.

 

[fissioneng]

sounds like short cycling. Low pressure shuts it down. If it is temp it usually takes longer to restart.

Not many units have a low pressure shut down. Neither of mine do, HP only.

 

[fixin-to-cruise]

Best thing to do is buy some gauges, connect them and watch the pressure readings when it shuts down. Just post the numbers here and you will be swarmed with good advice! A/C gauges are available for $25-50. Without them it's like trying to diagnose an electrical problem without a voltmeter.

I've seen a lot of A/C systems replaced unnecessarily.

 

[GJH]

What make and model of unit is it? You may be able to get a diagnosis via the factory's web site vs having to pay for one. I have a Mermaid on my aft deck and their trouble shooting guide made it easy, though they will help on the phone too. Do you have water flow?

 

[Bill Root]

Re: A/c "clunk" SOLVED

Problem solved. It tuned out to be a plugged water supply line causing the unit to build head pressure and overheat. Blew out the water line and it runs perfect now.

 

[Finalee]

thanks for posting the outcome.