cruisair help

[John C]

I have a cruisair 10000 btu a.c. with the smx 2 controls. I have no power at the control head. Is there a fuse somewhere in this unit? Thanks!!!

[Bruce]

There are fuses on the main circuit contoller board where the compressor SCR is.

Nothing directly for the control head since it is low voltage, but if main power is out, that will affect the voltage controller.

SMX controls use a modular phone or networking type plug. Make sure this is not loose or the pins/plug is corroded. This is the most common problem I've found on the SMX especially if the back of the contol head is open to air and not inclosed inside a box.

[John C]

Thanks Bruce..I went down to the boat and turned the a/c on and it worked. Left the boat for a minute and the controls went dead again. Over the next hour sometimes it came on and sometimes it did not. I am not starting the compresser due to the fact the boat is out of the water, I will give those conections a try

[In Memory Walter K]

Could it be your AC is cutting off because you're out of the water? Walter

[John C]

Yes Walter that would happen if you tried to turn it to heat or cool. I am just powering up the smx 2 control head and its cutting on and off.

[John C]

Bruce all the connections look clean and tight. I put a meter on the control head and got 5 volts. Any way to trouble shoot these things?

[Bruce]

other than having acess to a scope and the knowledge to diagnose circuits, not really.

One thing I look for in intermitant problems that use circuit boards is cold or bad solder joints and or tracks. May work for years and suddenly act up. Also look for the main wire connections at the circuit board and make sure they are not burned or loose.

I'd also put a meter on the main power in and when you cycle the control head make sure that power stays on with proper voltage.

Check both the main and control boards. Other than that for time sake, I just plug in a new control, cable or if that don't fix it a new main board. Very rare has a chip set gone bad. Most all the main boards I replace are because the compresser scr burns out.

Unless you can find someone to lend you some spare parts, i would suggest getting a local dealer to send a tech out. In a hour or less they should be able to nail it down.

Otherwise its buying parts that you can't return.