Crusair High Pressure shutdown

mistercomputerman

mistercomputerman

Well-Known Member
Jan 6, 2008
4,321
Virginia Beach, VA
Boat Info
410 Sundancer - 2001
Engines
Twin 8.1L Mercruisers - 2009
When I crank the AC in the forward cabin down really low, after a while I get a High Pressure shutdown on the unit. (Unit is new last year, so I doubt that it is refrigerant)

Strainer is clean, water flow appears normal from both overflows, filter is clean, unit runs normally unless you take the thermostat down into the 60's.

I think a High Pressure shutdown is from high head pressure which I think comes from low water flow. I seem to remember someone had a similar issue, but, I cannot find the post.

Any ideas?
 
I learned about triggers from what you are experiencing. When you say "normal water flow", does that mean when you see the HI PS error that the water is flowing? Or is it possible the water is flowing when the AC is working and then when you get the HI PS warning that maybe the water wasn't flowing?

You have two AC units driving a single water pump. There is a box that contains two triggers that essentially turn on the single pump if either of the units is running. What can happen (and this is very common) is the trigger in that box for one of the AC units is bad (the forward one in your case) and so the water will flow when only the AC unit with the good trigger is running (the salon in your case).

You need to turn off the salon AC and turn on the forward AC and see if you still have water flow... you may not...

It took me several weeks to diagnose this problem the first time it happened to me as the damn water would work sometimes and sometimes not... I thought it was Gremlins.
 
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it shouldn't matter what your t-stat is set on. the compressor is either running or it isn't. and you are right, the condition is caused by loss of sufficient heat exchange. I've had my pump get vapor locked and lose water flow and give me the HI PS message. it doesn't make any sense that your a/c could run fine all day and then when you turn it down you get this message. the only thing turning it down would do is cause the compressor to run all the time and not cycle on and off.
 
What Gary said. Do you have both AC units set very low...60? If so, the salon unit may be cycling off sooner than the forward unit.....and when the salon unit shuts down, if the forward unit's trigger is bad, then the forward unit will fail with HI PS.

Changing out the trigger on the 410DA will take you about a half hour. It's located behind the salon sette just under the electric panel. You have to remove the backrest bolster....or whatever it's called....and the triggers are in a control box right there.

Buy two triggers....and staple the spare right in the area where the box is for the next time....that's what I did.

BTW....if you don't have time to do the job or get the part before you head to AC, there is a cruisair rep who keeps his boat docked at Farleys Marina in AC.....he should have the parts in his truck with him.....mine went last July 4th and I simply walked over a few docks and picked up the parts.....let me know and I can get you his number so you confirm he has the parts and that he will be there.
 
Four Suns said:
I learned about triggers from what you are experiencing. When you say "normal water flow", does that mean when you see the HI PS error that the water is flowing? Or is it possible the water is flowing when the AC is working and then when you get the HI PS warning that maybe the water wasn't flowing?

You have two AC units driving a single water pump. There is a box that contains two triggers that essentially turn on the single pump if either of the units is running. What can happen (and this is very common) is the trigger in that box for one of the AC units is bad (the forward one in your case) and so the water will flow when only the AC unit with the good trigger is running (the salon in your case).

You need to turn off the salon AC and turn on the forward AC and see if you still have water flow... you may not...

It took me several weeks to diagnose this problem the first time it happened to me as the damn water would work sometimes and sometimes not... I thought it was Gremlins.
Click to expand...


Ding...Ding...Ding...Ding...Ding...Ding...Ding...Ding...Ding...Ding...

Give the man a prize. No water when the rear unit is off.

I appreciate the prompt (and correct) diagnosis.
 
osd9 said:
What Gary said. Do you have both AC units set very low...60? If so, the salon unit may be cycling off sooner than the forward unit.....and when the salon unit shuts down, if the forward unit's trigger is bad, then the forward unit will fail with HI PS.

Changing out the trigger on the 410DA will take you about a half hour. It's located behind the salon sette just under the electric panel. You have to remove the backrest bolster....or whatever it's called....and the triggers are in a control box right there.

Buy two triggers....and staple the spare right in the area where the box is for the next time....that's what I did.

BTW....if you don't have time to do the job or get the part before you head to AC, there is a cruisair rep who keeps his boat docked at Farleys Marina in AC.....he should have the parts in his truck with him.....mine went last July 4th and I simply walked over a few docks and picked up the parts.....let me know and I can get you his number so you confirm he has the parts and that he will be there.
Click to expand...

Dom

Got the backrest off and have both Cruisair boxes opened. What's a trigger look like?
 
I forgot....you have gas motors.....I'll bring some of my what I smoke to AC next weekend......
 
As Dom said, when you order a new one, get an extra one or two... and put them in a baggie and tie wrap/staple them to the relay box. Losing AC on a trip around VA/MD/NC just plain sucks. These things fail more than an Obama economic plan.
 
osd9 said:
What Gary said. Do you have both AC units set very low...60? If so, the salon unit may be cycling off sooner than the forward unit.....and when the salon unit shuts down, if the forward unit's trigger is bad, then the forward unit will fail with HI PS.

Changing out the trigger on the 410DA will take you about a half hour. It's located behind the salon sette just under the electric panel. You have to remove the backrest bolster....or whatever it's called....and the triggers are in a control box right there.

Buy two triggers....and staple the spare right in the area where the box is for the next time....that's what I did.

BTW....if you don't have time to do the job or get the part before you head to AC, there is a cruisair rep who keeps his boat docked at Farleys Marina in AC.....he should have the parts in his truck with him.....mine went last July 4th and I simply walked over a few docks and picked up the parts.....let me know and I can get you his number so you confirm he has the parts and that he will be there.
Click to expand...

I emailed the local guy to see if I can grab a couple tomorrow. If that doesn't work, I'll chase you down and get the AC AC guy's number.
 
I hope you have better luck with the local Cruisair guy than I did last year. I was on the phone with them last June trying to get a blower motor and the guy was one arrogant SOB. He would not sell me a part alone but needed to do the service as well. The problem was he couldn't do the service for 4 weeks... and I was getting ready to leave on a trip. I explained that to him and his response was "that's just the way it is." He explained he didn't sell parts but a service and he had an exclusive so there was nothing I could do... He would not sell me the blower so I ended up driving to DC to another shop to get the part.

I hope the guy chokes in the current economic downturn... you can tell him I said "hi"...

As an FYI, the triggers are available from several online sources...
 
Based on my experience last year changing out the forward unit, I can see that happening. If I hear the same song and dance, I guess I'll FEDEX am a couple for Tuesday delivery.

I appreciate the help.
 
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