Last night all of the sudden, the registers stopped blowing cool air. The indoor fan is still running and blowing air, there is just no temp split at all in relation to the rest of the house. The fan outside on the condenser is kicking on. What are the possibilities, and what tools are needed to check. I want to figure out what is wrong myself, and then pay someone to fix it only if it will require messing with the refrigerant. Also, this is a relatively new unit(~5yrs old) but I cannot find the paperwork that we got when we moved in.

Inside model#: Bryant FB4ANF024
Outside model#: Bryant 693DN024-C

Is the compressor running? Out door fan maybe ,but not the compressor
Maybe the filter is dirty (no circulation),, look at and replace if needed
Maybe the evaporater coil froze up (no circulation)due to dirty filter or low on freon
Or has maybe someone closed off several supply vents
Maybe the evaporater coil is very dirty (no ciculation) needs cleaned

UPDATE:

Problem fixed!
Before reading, note that I am NOT a professional. If you use any of the procedures listed below, you do so at your own risk and responsibility. Electricity can kill, and you can do more damage than good to your equipment if you do not know what you are doing.

First of all I should have been more clear when I originally posted, but my lack of knowledge on the subject limited my post. When I said that the outside fan kicks on, it actually clicks and sounds like it is trying to spin but doesn't. I stuck a letter opener in the grate and manually spun it and it picked up speed and kept running on its own. So, now that your all up to date... I called my uncle yesterday, who used to install heat pumps, and explained my situation. He said that there is a capacitor that is used to get the fan to start spinning that has two posts on it, and there is also one that is used to get the compressor to start up with two posts as well. He also mentioned that sometimes there is only one capacitor that is used for both and has 3 post on it (one constant, one fan, and one HERM). He said before you test the capacitor(cap), discharge it by shorting the constant with each one of the posts to release any charge. Also, make sure you have the turned off the power to the unit from both the inside breaker panel, and the outside dedicated panel for the heat pump. He told me that to check the capacitor you need a analog multi-meter that reads up to at least 20k Ohm, or a digital one that reads up to at least the uF (Farads) value that the capacitor is supposed to read. If you use a analog one, you set the meter to Ohm and connect one lead to the constant and the other to one of the other posts. The analog meter should slowly rise and peg out the meter, then it will drop. This indicates a good capacitor. If it just rises and does not fall, or if it doesn't rise at all then it indicates a bad capacitor. If you use a digital multi meter, you just set the dial to read uF and connect one of the multi-meter leads to the constant, and the other to one of the other posts to get the uF reading. It should read on the digital meter close to the uF that the capacitor is rated at. Mine read (OL.) which means that it is shorted out. I picked up a new capacitor today for $9 (5-uF/35-uF, 370-VAC), popped it in, and the air came right on. I checked the temperature split between the coils(air return temp compared to the air register temp), and it was right at 15 degrees F, which is what it should be. Hope I wasn't too long winded, but hopefully this will someday help someone in the same situation who isn't lucky enough to have a knowledgeable uncle a phone call away.

p.s. local hardware stores do not sell capacitors for HVAC applications. You have to go to a dedicated supply house such as RE Michel. Also, these supply houses require you to have a business account with them, or you have to show a HVAC or Home improvement license, or they won't sell to you.

and it was right at 15 degrees F, which is what it should be

Sorry but you TD or split as you call it is a bit low for perfection.

Glad you got it fixed

PS not all digital meters has uF capacity

It works now! Thanks to you and your HVAC uncle!

My Bryant Heat Pump fan stopped working too on a 100 degree day in San Antonio, Texas. I used a sprinkler stake to give my heat pump fan blade a helping push through the grate. It sustained spinning 'til the fan motor "on" cycle went off. Using this as my symptom, I found your post like a beacon on the internet. I tested my dual run capacitor with a digital multimeter. Your instructions were helpful in this regard but wikihow shows how to test start capacitors a little better: (How to Check a Start Capacitor - wikiHow.) I ordered the capacitor - UPS next day $60 shipping - $29.99 for the capacitor - from Heating and Air Conditioning Parts Direct to the Homeowner

I was miserable without AC. It broke on a Sunday night. I called a 24 hr plumbing HVAC company to come out and fix it. I am so glad that the technician talked his way out of coming out (said he'd have to charge me 179.00 to come out and he probably couldn't fix it as there were a limited amount of parts on his truck. After reading your post and pulling the capacitor, I had the tech call me back and asked if he had this part on his truck and how much it would cost. He didn't have a dual run capacitor and would have to combine two separate ones to perform the function. He said it would cost three o seven for the part and 179.00 to come out. I asked him if he meant three dollars and seven cents. No, three hundred and seven dollars.

My internet service just paid for itself for the entire year!

Thanks for you pot I get same problem My central air not cool find out dual run capacitor is blowed, I pickup on grainger store {brand name is Dayton Dual Motor Run Capacitor (part # 2MEG2), MFD Rating 80/5, Voltage 370, 60/50 Hz, Round, Dia 2 3/8 In, Height 4 3/4 In, 2-blade Quick-connect Insulated Terminals, Temp Range -40 to 70 C, Hermetically-sealed Aluminum Case with Terne-plate Cover, about $30 + tax}

Thanks for this, I did the same thing in the beginning of summer I have a rental that same thing started the blades with a twig but no cool. Im not even going to bother testing I take a picture of each capacitors wiring go down to the supply house and 20 bucks later it SHOULD technically work.. good idea to buy a spare the heat kills these things