To all:

To summarize: the intake, the outflow, freon, etc. have been determined to be fine. I guess what I'm really trying to evaluate is the blower motor itself. It is a multi-speed type, although only 2 speeds are used (med & high). Has anyone experience a motor that intermittently doesn't come all the way up to speed? When it does this, I can usually power it down with the safety switch - bring it to a complete stop, and (with the access cover off) bring it up to full speed by depressing the safety switch. Is it likely the start cap or motor itself? How can I test adequately the motor and cap. Motor turns freely without bearing noise and the technician said cap was okay - but I think he only did a ohm-meter test which is not adequate in all cases from what I've read. Ammeter readings seem okay whether the motor is running normally or abnormally - current draw is not increased in either. What's a definitive test for the motor and cap besides simply replacing them (which is where I seem to be headed at the moment)?

3 things cause freezing coils

1. low refrigerant levels
2. low outdoor temps (typically below 70'F)
3. low airflow on the indoor coils.


Your blower motor may or may not be the culprit here

Check all these conditions before condemning the motor

juggallojed:

Read previous posts and you'll find...
1 - refrigerent levels okay (multiple checks by multiple techs).
2- temps here about 100'F in the shade.
3- I'm tired of guessing and already have the replacement blower motor at hand - just waiting until the cool of night to install it.
If anyone's interested, I'll do a follow-up post to let you know if that cleared up the problem...

Please do post your results.

This is prpbably too late to save a motor but did you ever check the tempature drop over the evaperator coil... or a more likely problem is a evaporator coil that is partially stopped up with lint, dust, pet hair, carpet fibers, and any othe thing floating around in the air that is suppose to be stopped by a filter, which most don't work but about 50%.

To All:
It's been over a week and not one episode of freeze up since I installed the new blower motor. I will add the following details that may help others in the future: the motor I was replacing was not OEM but a generic substitute (Fastco) that the supply house said was equivalent. The original motor had been in place for approximately 12 years until the bearings went out - the Fastco only lasted about 6 years. Live and learn - I suspect a faulty winding on an inferior replacement (Fastco). The new motor I have just installed is OEM - a bit more expensive but likely worth it. I was able to get an AC shop owner to get it for me at cost and I installed it myself - both of which saved me a bundle... I am in the midst of writing a complaint to the original AC shop which sent out a total of 4 technicians and failed to fix the problem - of course, they sent me a bill for all 4 attempts - what nerve!! Take away from this - if all else fails to stop occasional freeze up (low freon, block / restricted airflow, etc.) - don't dismiss an intermittently slow blower motor.

(Please look out for a new post soon on an AC drainage problem at another location and how I solved it)...

Thanks for you update.

Sadly, I've had similar results with HVAC techs in my area. I had to pay 3 times to have a tech come out and each had a different story. Ultimately, I fixed it myself.