A little history:

Once and awhile the heater fan ( set at 2 or 3 ) would speed up to full speed then back down a couple times in
2-3 seconds then it would be fine. This would happen maybe a couple times a month for the past year. other
then that it seemed to work fine.

Today:

Heater Fan set to 2, temp=72, AC not on.

The fan speed went to full speed. I could shut it off, but once I turn it on, it went back to full speed and the air
coming out of the vents was cool. I turned the fan speed and temp control to Auto to see if that did anything,
but it didn't. I did notice if I turned the heat dial from 74 up higher it did get warmer.

Any ideas? Could it be a sensor or the control unit for the climate control?

Thanks,
Ed

 

Could be the blower motor resistor.

 

It's working now. All speeds. I do not think it was the resistor.

What would make the air get cooler?

Does the CCM give a diagnostic trouble code?

 

It will but not many if any Cheap scanners can read them.

You might also need a software upgrade.