Hi Don…Thanks for posting~

First I would look for the end of the temp cable (the part that senses temp) which is usually located in the return air path to the air handler…Be sure that with the system cooling…That none of that cold air is leaking back onto the sensor (the rats may have eaten thru a cold air duct and it is blowing onto the sensor)

After you verify that's not an issue then look for/do the following….

1999…That's about the time that Cruisair made a circuit board change that instead of using flat connectors & round wire for the temp sensor & control cable…They changed to flat cable & telephone jack type connectors…

I can see rats easily eating thru the newer flat telephone type cable but it would be a bit harder for them to eat thru the jacket on the round cable…

As far as a temporary fix until you can get a new sensor cable…I would look at the cable for the chewed spots (even if you have to remove it)…The round cable can be repaired easily by cutting out the bad spot & reconnecting the wires with typical crimp type butt connectors…The telephone cable is a bit harder to work with but can be repaired with cable splices that are meant for that flat cable…I'm not sure about in Guatemala, but here just about ever Home Depot or Lowes stocks those splice connectors…Maybe your telephone company can help if you can't find them in a hardware store…

I would then do a factory reset of the control as described in your manual…This will get everything (including your temp) back to the factory preset baseline…When it's finished, and if you have made your repair/s properly the temp reading should be pretty close to what it actually is at the sensors location (it should be no more than 2 degrees off)

You can also verify operation by wrapping your hand around the sensor end & see if the display changes (make sure you have pressed the temp button, and the little light indicating setpoint is not lit)

If you are still having issues after all that, then we either need to look at replacing the board or the sensor…But your response to the above will help with that answer of which to replace…

Steve~

the phone system in guatemala will not let entries to the phone pad after the call is placed. i need a direct phone number i can use in order to place an order for parts. the parts will be shipped to st. pete. as soon as i can figure out what to buy. i know you are in tampa, you installed this system for me in 2005.

the boat was at the viking boat yard when it was installed in june of 05. the sensor cable needs to be about 40 ft.

is there a chance something else could be wrong as it is a LONG way back to the boat from st. Pete. i don't mind buying extra parts as i eventualy use them. if there is a chance the circuit board or thermostat is bad i would like to buy them. the extra expense goes along with cruising on a permanent basis.

i will try and call from guatemala monday, but would prefer to order online and have parts sent to my st. pete UPS mailbox so i can pick them up on may 9th. if this is possible please let me know.

ok i'm back from the big city w/ parts. you guessed it when i went to replace the temp. sensor it was corroded at the condenser, it is now clean and working.

i now have two extra thermostats and would like to replace the smxir display with one of the newer ones. can i use the passport i/o disp. 222000222 to replace the (on the back it states; factory set for split capacitor) smxir(black door) or should i use the 222000200 psprt-i/o display to replace the smixir.

is either one of these a direct replacement without doing anything except plugging it in?