5 ton Carrier Infinity control board compartment on the outside unit has a red light on the underside of the compartment flashing. What does that mean ?

That unit is a very complex machine. The temp sensor out of range issue may be as simple as the sensor being unplugged, or the sensor/outdoor control board needs to be replaced. The "range" it states it an ohm value in the sensor, that the board cannot evaluate properly.

The best information you could get is from Carrier. Here's their website:

http://www.carrier.com/homecomfort/en/us/for-owners/

There is a toll free number to call 1-800-Carrier (1-800-227-7437)

board bad

The cooling light not coming on, on the ac unit

Is the furnace fan (indoor fan ) running. If not the problem is with the inside unit. It supplies the control power to operate the entire system and has a control fuse on the circuit board. If it is running but not the outside unit then the problem is outside.

There should be a little black sensor bulb outside either on the unit normally under the electrical panel or inside it. It sound like the wire has come off or been disconected. It needs that on to properly run. Your control is trying to communicate with the outdoor unit and can not.

they should attache to the Y on the control board and C.

Make sure all wires are hooked correctly ABCD should match. The Kill all power try again. When Infinity control is hooked up correctly it by passes all dip switch so that it can communicate with the tsta furnace and outsid unit. Rus

I work on Carrier Infiity systems. The outside board has a Model plug on it. This tells the system what size unit it is. They do go bad. You can reset your self by turning the power off to the Air Handler. These system have 10 year warranty and if you still have a problem have the replace the outside control board and model plug. Also you can contact Carrier on the their website and get answers. You may need to talk to a service rep in your area. Carrier is good about their Tech support. You should have to pay for a service call if you your problem continues. Sometimes power surges or stoem cause these problems but not often Rusty

Have you eliminated the possibility of a high or low pressure error. Sounds to me like it's off on safety. Should have troubleshooting the flash right on the panel. Test your pressure switches for continuity.

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