SMX II problems

[rourkeh]

I am trying to replace a small digital Cruisair control panel with a SMX II that I ordered
The A/C unit is a Cruisair 12,000 btu split unit with a Cruisair control box with a model # STQ12C and product # 205-363550. I also ordered a new connecting cable that has the 4 pin plug on one end and the telephone jack type plug on the other end that goes in the control box.
When I hook it up it powers up but the display reads hh and nothing functions.
What am I doing wrong????

[MadHatter53]

I found a lot of good info here when I was having some issues. A google search always works for me.

[Briankinley2004]

Here is a good starting point. You can call Flight Systems or email them as well and they are very helpful

https://www.flightsystems.com/pdf/cr...ting-guide.pdf

[jrmccoy]

I had an issue like this when I had to replace a self contained AC in the master berth. The new unit had identical connections for the existing keypad/thermostat (an RJ 11 or 45 plug can’t remember) so thought I was golden keeping the previous SMX keypad. Plugged it in...didn’t work. Apparently, the keypad has to be closely matched with the unit model and there is variability. I went back to my AC shop and bought another keypad that looked the same, had same connections, and exact same form factor as the older one....but there are obviously technical differences, because the new one worked.