On Thursday, June 19, 2014 7:50:37 AM UTC-4, Davej wrote:
On Thursday, June 19, 2014 6:39:38 AM UTC-5, trader_4 wrote:

On Wednesday, June 18, 2014 10:16:26 PM UTC-4, Davej wrote:



So the compressor runs and then at some point the A/C

decides to turn on the blower fan. Mine works fine for

awhile, but then it starts turning the fan on and then

off again, within a few seconds, as if it can't decide

whether the coil is cold enough.





Are we talking about a central AC system that's part of

a furnace?



Yes



IDK what the latter does, but in all the first two types

that I've seen, the coil temp doesn't control the blower.

The blower is turned on and the compressor start at the

same time. When it shuts off, the blower typically stays

on for another minute or two after the compressor goes

off.





Hmmm, you're right. I thought it worked identical to the furnace but apparently not. I've had this strange blower fan operation ever since the furnace was installed and have used continuous fan to avoid it, but now even continuous fan has strange behavior.

You need to put a meter on it and see if it's getting power but not running or if the control board is not keeping it powered.