AC Passport I/O Control operation

[Cherylynny]

Hi y''all, having trouble with the display to operate the AC. I have a 366 Carver MY. The system was working fine on heat a few weeks ago (Canada eh!) and when I tried to operate in AC it just won't respond. Lowering the temp does not kick in the cool air. I reviewed the Passport I/O manual and tried program mode but instead of "P" coming up, I get a "U". No where in the manual is "U" discussed. If I press on some more a code "A26" comes up which also is not in the manual. Does anyone have any experience or advice on this problem? thanx.

[buster53]

Try it again in heat mode. If that works, a good chance the transfer switch is shot. The transfer switch is what switches from heat to cool and back to heat. It's an expensive repair. Happened to us some years ago and since we rarely used heat, we had the AC repair guy to manually put the switch on cool and it worked just fine.

[g36]

I have this on my405 but not at boat right now. Make sure you are in off mode while trying to enter program mode. While off press ans hold power till p comes up. Use the fan button to select different parameters and then up and down to change. The A26 I believe is your software version and not an error code. If you are seeing this inbelieve you actually are in programming mode. When you select cool mode does the led by cool light? If not its probably in heat only which does need to be changed in program mode. Also .I do not use the auto feature I use cool only and heat only depending on time of year.
Remember it will time itself out if no buttons are pushed in 50 sec I believe

[Cherylynny]

:Hi g36, the problem I am having is actually getting it into program mode. When I press the power for 5 secs a "U" comes up then A26 flashes. I can't seem to get into program mode. Is there something I can reset? It's neither in heat nor cool mode but the middle fan mode (but no fan running). I agree, I don't like auto feature either.

[km1125]

Make sure you're using the right manual for the display you have. They have several displays are very similar but have different programming commands or keystrokes to do the same steps.

[g36]

Assuming same oem from marine air systems the passport i/o has a factory automated self test program built in. Page 20 of the manual describes this feature . Turn off breaker to hvac unit. Once you start this it will test your unit automatically. To start it you will probably need 2 people. Press and hold the power button and while still holding power on the ac electrical breaker to the unit. Then release power button all leds will be lit and 888 in display. Once started it will cycle heat 10 minutes then fan only for 5 min then cool for 10 and then fan for 5 min . It will continue this sequence tI'll you turn off ac breaker or pressing the power button. If this will run you can at least know if your hvac unit is working and narrow down a issue with the control panel.