Post edited 2:09 pm – September 11, 2011 by Steve Pooler

Hi Robert, and thanks for all the detail…With humor 

conforte said:

Robert (conforte@optonline.net)

1998 Formula 31 pc

Long Island, New York

Water temperature in the low 70’s

Cabin temperature in the low 90’s

 

Marine Air / Dometic with a Passport II (Factory Installed)

Product: 205-500100

Model: VRP-12K

Reverse Cycle

SN: B8-M49039

 

Preface:

 

All summer the cabin stayed at a comfortable 62 – 64 degrees… until our last trip….

Geeze…62-64 degrees ?…Down here we would be puttin on a jacket or sweater…

Truthfully though…A/C is not really designed to operate in the cooling mode in ambient temps much below 68 degrees before they start icing up…The only reason they allow a t-stat setting that low is for the heat mode…But this is not related to your issue…

 

First of all, the raw water pump, mounted in the bilge was a rusty, crusty mess the day I bought the boat 2 years ago… I was skeptical of it's life expectancy then, but… well… If it's not broken, don't fix it…

 

Day of Downfall:

 

With the A/C power on, I leave the boat and return to find the cabin a balmy 77 degrees (while being set at our customary 64).

First thing I notice is there is no hummmmm from the compressor… the Passport II Control panel is lit, and the circulating fan is running…. I then check and there is no water being pumped out of the back of the boat… open the engine hatch and the pump is dead… give it a couple of wraps with the back of a screw driver (a.k.a. "the persuader")… nothing…

 

I check the strainer… clean… open the bleed and get water flow… so, there’s no “air lock” on the pump.

There is no flow sensor per say but there is a high pressure switch…Only reason that the Passport II would not send power to the pump is if there was no flow after it started the compressor…Without water flow, and with the compressor running, the system head pressure would rise to 425 psi (normal with your water temp would be around 220 psi) it should then shut off both the compressor & the pump with a fault code on the display…

You would then look for the no flow culprit (air, clogged strainer, or bad pump ?) then reset the control by cycling power & try again…This clears the fault & all should start in order again…Fan, Pump, then Compressor… 

 

Back at the dock I grab a non-invasive tester and find there is live current at the pump…. so the line from the electric box is live. I don't know HOW MUCH current, but with the power off I get a negative reading, with the power on… positive.

While these type testers are safe…They won't tell you how much voltage is present…Only that there is voltage…

 

I cut the pump out and order an exact replacement (Little Giant).

 

In the meantime, I hook up my high volume garden hose to the water line feeding the compressor… now I have cold, fresh water running through the line and heavily pumping out the back of the boat…. so there's a nice cool water supply…. and obviously no blockage.  Keep in mind, this hose is pushing about 1,000 gallons an hour, so the supply is heavy.

 

Now I throw the power and everything comes to life but the compressor (remember, the pump is disconnected)

See above…It does not need the pump present, or even any flow for the compressor to start…It only looks for the pressure switch fault…If there is a fault it should show on the display…Normally this takes compressor run time to happen…Enough time that the pressure rises above 425 psi…With no flow it might be as long as a minute on first start…Subsequent starts the time is shortened, because without that water flow, the condenser is now hot… 

 

I guess the question is…. When the raw water pump failed (which you will learn, might not have been the case in the first place), did it damage the compressor or the circuitry?… does the A/C brain know there is no pump running? And, when I install the "brand new" replacement pump… should I expect the system to come back to life?  I have a lot of meat hanging in there that's gonna go bad.

In the temps you describe…Our meat would be all shrunk up anyway… 

 

Two Weeks Later:

Well the new pump arrived, and I assembled and reinstalled…. powered up the A/C (which now has been sitting for 3 weeks)..

 

a. The new pump is not pumping water… actually, it’s not turning at all… but when I test the line with the “non-invasive” tester, there seems to be some sort of power/electric flow.

 

b. The control panel comes to life and when I held the button for 10 seconds to Factory Setting Reset I received an "A.17" code,

A-17 is just your software version…It's supposed to show every time you leave the program mode.

 

c. The circulation fan comes on and nicely blows the clammy 85 degree air around the cabin

 

d. I do get a definitive "click", as if the electric box is sending a signal to the compressor or pump, or well… something is turning on and off.  I suspect it's either a breaker or a relay, but either way… the system is failing.

This click is usually the Reversing Valve energizing before startup to ensure equalized system pressures…It's normal…

 

e. I downloaded and read the manuals and it makes reference to the "Pump Circuit Breaker – if applicable" but after scouring the boat, I couldn't find a related breaker, so rule that out. Plus, the factory wiring diagram shows no breaker exists from the electric box to the pump.

The breaker they describe is for a pump relay box which is only installed if you have more than one unit supplied water from a single seawater pump…

 

f. The troubleshooting guide makes mention of high pressure valves stuck open or closed…

There are no High pressure valves…I think they are referring to the high pressure switch I mention…If it were faulty you would get the HHH fault soon after you entered the run mode…

 

g. The electric box doesn't appear to have a button or reset switch, and even more odd… I can't figure out how to break into the thing… there are no visible screws or latches….

There is No reset switch…The only reset is clearing the fault on the control by cycling power.

The box should have 2 maybe 3 small Phillips screws that hold the box portion to the mounting base…

 

Does anyone have a little insight as to the next step?  Is there a "Magic Reset" somewhere to kick the system over?  I am NOT getting “PPP” or “HHH” codes for Freon failures.  I think the nature of this problem lies in this box.

 

I have read through some of the forum entries and I believe a relay may be bad, or burnt…. 

If I determine this IS the problem, what are some options????

 

The boat (and air conditioning) is a 1998 – Marine Air / Dometic with a Passport II

Product: 205-500100

Model: VRP-12K

Reverse Cycle

SN: B8-M49039

 

Any input… Please

 

Thanks,

Robert

 

Robert…It seems you have bad compressor & pump relay/s on the Passport II board (inside that box) that are non field serviceable…If so…You must replace the complete board…Unless there is some other burnt connection inside the control box…

 

Yes your Passport II board is available but it's actually $5.00 more than a complete retrofit kit to the newer Passport I/O control system…

 

It does not make much sense to replace your board when they do not offer a replacement keypad/display for it anymore…It's better to go with what can be replaced in the future for less money….

 

If you would like me to quote the kit…Please send me an e-mail thru the contact Steve link at the top of any page on this site…

 

Steve~ 

Robert…You should have mail…

Steve~