My A/C Diagnosis

[tomschauer]

Rick, my guess would be that the older stat is not compatible with the new controller and it is operating in some sort of failsafe mode.

[RGrew176]

They are identical model thermostats. However the original is from 1996 so there are changes to the card and possibly changes to the thermostat to align with the newer card.

I am going to order a new thermostat cord too just in case the old cord does not match up with the new card and thermostat. That's what tech support suggested. I just wish that they had suggested that when I ordered the other 2 parts.

I am heading out on Monday for a 7 day boating vacation so I won't get to try the new cord until the following week. At least the A/C is functioning probably in a factory default mode as it is holding at 70*. It's supposed to be a warm week so the A/C will be nice to have.

[tomschauer]

Enjoy your seven days on the water!!!!

[Midnightsun]

Enjoy the vacation, weather for the week looks great.

[RGrew176]

Thanks all. If the winds are calm I am planning to head out across the lake sometime around 3 AM. Will be running slow about 1200 to 1300 RPM until the sun rises then I will get up on plane the rest of the way. Should be a bit of the moon. Saturday morning was a half moon so I should have a bit of light.

[RGrew176]

Final update. Yesterday (wednesday) the A/C guy was back on my boat to install the new thermostat cable and adapters. We first tried it with the new thermostat. When I turned on the breakers for the A/C the thermostat display lit up. We ran it through both the A/C and heat cycles. Tried all the other buttons to make sure they all worked. I now have a functioning A/C system once again and with it being 90* yesterday it was needed. Hope this if my last problem with that system for a long time.

We also hooked up the old thermostat to the new cable and it also functioned so I will be keeping it as a backup in case the new thermostat crashes in the future. My A/C guy said that this is the first time in his 35 years of working both home and marine systems that he has seen a thermostat cord go bad. I guess there's a first time for everything.

678.40 A/C System Electronic Card and Thermostat at Boaters Value
233.17 A/C Thermostat Cord & Adaptors at Boaters Value
561.00 Marine HVAC Service Call at Burgin Heating

1472.57 later I have working A/C system once again. I did price out a new unit for $1700 + tax and installation. I did save some money over a new install. He tested the unit and even though it's 22 years old it's functioning quite well. It puts out 54* air at the discharge vent into the salon so it's pumping out cold air.

[g36]

just curious what your lake water temp is up there. here in tennessee the lake water temp right now is 86 degrees.

[RGrew176]

Source of the post just curious what your lake water temp is up there. here in tennessee the lake water temp right now is 86 degrees.

We are at 77* at the moment but with cooler weather coming that will soon start to drop off.