Cruisair problems

[mwert72655]

My now 4 year old "newest" A/C is acting up and the locals can't seem to diagnose the problem. It has the SMX II controls and the light comes on indicating the compressor should be coming on, but never does. The raw water pump does kick in, but only after a significant delay, and then it fails to turn back off after switching over to fan mode only - in fact sometimes the only way to get it to turn off once it's on is to cut the power to the unit at the breaker- previously the relay for the water pump would kick on and off immediately. This sounds to me like a control/circuit board problem but we replaced it already with no benefit. Any thoughts?

[Trojan]

It sounds like it may not be the controller. When the pump comes on check and see if there is voltage to the compressor. The water pump should come on then the compressor should come on. The unit may be looking for the compressor to start and it is not starting. You may have a starter relay bad. I can't remember the color of the wires for the motor. I think its blue and yellow. It should have a color label on the inside the cover on the compressor. The newer units start and stop the water and compressor together. The older units run the pump all the time the AC is on.



BILL

[Genesis]

Does that unit still have triggers? If so, there's a thread here about them things..... they like to blow up in precisely this sort of fashion.

[mwert72655]

It used to be nearly simultaneous if not exactly simultaneous on and off. Now it delays well after the compressor light comes on and then doesn't shut back off. I bet it is the relay as we've already replaced the controller circuit. Thanks in advance for your thoughts.

[TedZ]

Sounds like a bad flow switch. I think those have a switch that "proves" when the unit sees water flow. That usually causes a very short delay in the compressor start when you turn the unit on i.e. pump starts, proves the water and starts the compressor. Shouldn't be hard to find...follow the water lines and look for wires going to a flow switch in the line.

If they are sluggish they won't make cleanly and they won't turn off reliably.

Ted

[Trojan]

That was my first thought. But my new unit did not come with a flow switch. So I thought that if he started with the compressor and worked back he would find where he lost voltage.


BILL