Forward AC unit stopped working

[MadDog]

Forward AC unit under the master bed stopped working during my extended trip this summer. Any pointers? Here's what I know.

1. Wall control panel for this unit shows nothing, but I've confirmed by swapping the panel out to the center AC unit the panel is working fine.
2. the breaker for the unit is fine.
3. There is power to the unit - confirmed with a voltmeter on the AC unit.
4. The filter is clean, the sea water strainer is good etc.
5. The other two units that share the water pump are working just fine.

I noticed by searching the forums a few folk have noticed loose wires/crimping etc so i'll look for that.

Any clues? Thanks in advance.

 

[elreyos]

I had a simular problem this past spring. In my case it was a bad breaker. The experts told me if the panel and power proved good the next item would likely be the control board on the AC unit. You've done every test I did, mine was no power to the unit. Maybe you could try swapping the circuit boards.

 

[MadDog]

Thx, elreyos.

I also think there is at least one thermal breaker on the unit. I need to check that when I next go to the boat.

 

[tobnpr]

Not working- nothing, not even the blower?
Make/model? Does it have a separate control box? Since you have voltage to the unit, and the control is good, I'd suspect a bad circuit board, somewhere.

 

[MadDog]

Nope, nothing.

It's a standard cruisair package, don't have the specs right now and all of the units have a single remote box for the water pump. I'm suspicious one of the delay fuses in there might be dead but agree the AC unit circuit board needs a look.

 

[Four Suns]

I'm always surprised that front AC unit doesn't break more often... it's in the worst possible place for abuse as my kids will lay on that bed so they can "hit the ceiling and hit the bed" in big waves...

No idea on the issue... I had to actually screw the front thermostat panel to the wall because it broke off the plastic mounts.

 

[MadDog]

Both the forward and starboard stateroom panels are loose thanks to broken plastic mounts here too. Screwing them down is on my todo list...

When I get to the bottom of this i'll post my findings.

 

[elreyos]

BTW the circuit board I'm refering to is located on the compressor unit. If your boat is like mine the compressors are located in the ER.

 

[MadDog]

Update:

The culprit was a bad logic board. $275 and 15 mins of simple work later and all is well again.

 

[vanburen]

How did you figure that out? Just curious. Hope it didn't ruin your trip.

 

[MadDog]

Process of elimination. By swapping parts from the central unit, i was able to determine the root cause. The big giveaway though was the fact the control panel was blank. After swapping panels and cables it could only be the circuit board causing the "no power to the control panel" problem.

BTW Cruisair tech support were also very helpful in providing diagnosing options.

regards.