I have a 2000 Tahoe with electronic climate control. Regardless of how I set the fan or modes (dash, floor, defrost, etc.), the A/C almost always will not turn on. If I push the A/C button, it blinks 3 times. In the rare instances when it does turn on, it blows plenty cold and stays on for a while (10-15 minutes). This problem started last summer and slowly has gotten progressively worse. The refrigerant pressure has checked out fine according to my mechanic, but he can't find the problem. Any suggestions would be appreciated.

Try a recalibration on it.
Key off remove radio fuse for a minute and the install and turn key on and the ac should recalibrate from hot to cod mode.
If no help you will need to get it on a good Body PCM ac/heater capable scanner and check codes and operation.
Good luck and let us know how it goes.
MT

Many thanks - it worked like a charm. The only thing I would add for others in the future is that it is the main radio fuse, in the box under the hood - not the radio/audio system fuse in the box on the driver's side end of the instrument panel. :)

Many thanks - it worked like a charm. The only thing I would add for others in the future is that it is the main radio fuse, in the box under the hood - not the radio/audio system fuse in the box on the driver's side end of the instrument panel. :)

You are welcome and thanks for posting back how it went.
Good luck.
MT

More on that . . . .

It seems the recal is not sticking. Especially in Automatic mode, A/C doesn't seem to come on when it should. Have to turn it onto Manual mode (fan and vent selection) to start up A/C and even then it takes longer to kick in than it should. What next?

More on that . . . .

It seems the recal is not sticking. Especially in Automatic mode, A/C doesn't seem to come on when it should. Have to turn it onto Manual mode (fan and vent selection) to start up A/C and even then it takes longer to kick in than it should. What next?

Go back to post 2 if recalibrate does not help it is time to get it on a body capable scanner and see what is going on.
If you have any codes post back codes.
MT