I doubt the condensor unit was damaged. The evap coil in your AH iced up since the fan was not working.
12-15 years is about the time things will start "acting up" in the AH.
You will NEED an ammeter with capacitor testing capability. Sears and Harbor Freight are fairly inexpensive, if you don't already have one. Plus learn how to properly use it before heading up to the attic.
I encourage you to read over this several times before attempting this repair. If you are unsure or not clear on anything, ask before you proceed. There are a lot of good techs here to help.
Test the following:
1. Fan motor. Check the amp draw on black wire coming out of fan motor body. NLA (normal load amps) rating is on motor sticker if you can see it. This is the amperage the fan is designed to properly run at. Example: if NLA is 10amps, amp draw on meter will be consistently less than that (7-8 amps). If it pulls 10 or more amps, it will kick off on LRA (locked rotor amps). The fan will be inside a big metal enclosure. Try using an inspection mirror to read the sticker. Note:The fan mount band may be in the way.
Also check for 120vac between black and neutral (white) wires. It needs to stay at 120vac while trying to run. No voltage drop (less than 120vac) while trying to run. The black and neutral wires may be wired to the defrost circuit board. This is where you will take the readings.
Watch meter display, values may be displayed very quickly before motor shuts off.
*** Check the run capacitor before condemning the fan motor. See #2 below***
This is very difficult to change if you have never done it before. Fan wheel alignment is critical. Wiring new motor may be difficult (color coding of wires), access clearance stinks. You'll see when you get into it. Take lots of notes and pictures before you start and mark ALL the wires.
2. Fan motor run capacitor is bad. Check for a bulging top or any leakage. Microfarad rating will be printed on the side. SAFETY NOTE: Capacitors hold a charge even when power is removed from unit. Unplug AH from electrical outlet. Remove wires from capacitor. Take an insulated handled screwdriver and touch both leads of capacitor at same time for 2-3 seconds. This will discharge it, making it safe to handle and to test with your meter. Any value outside of printed rating is bad regardless of what the capacitor looks like. Look for a plus minus percentage factor (5 or 6 %).
3. Circuit board is bad. Your fan may be wired directly off a defrost pcb. Hard to test, but obvious burnt components is what you should look for. But your amp draws and voltage drop testing will tell all.
***Be aware of the safety switch on one of the panels you pull. You will need to push the plunger switch in to energize and test the system components.***
***Be aware that all wire connections need to be secure and tight fitting when reassembling everything. Use needle nose pliers to carefully compress any loose connectors. Loose connections create high resistance and heat and will fail eventually.***
Your fan motor is the most likely suspect here, and the most expensive. I would discourage you from "shot-gunning" parts. Take a logical, common sense approach to troubleshooting this, because working on this will not be that much fun and you don't want to be climbing in and out of the attic all day either.
If the fan motor is bad, replace the capacitor with a new one also. And meter test the new one before installing. It may be bad right out of the box.
This is a dirty hard job, especially in the summer. This will not be a quick fix, so the possibility of heat-related stress should be considered before you attempt this repair. If you have never done this before, I would estimate a minimum of 3-4 hours to complete start to finish for a fan motor replacement, even if you consider yourself mechanically inclined.
Hopefully it's the run capacitor that is bad and that job should not take as long, that is, as long as it is easily accessible.
You may want to consider contacting a professional to repair instead of DIY'ing it yourself.
Good luck. And remember, safety first. You are going to be dealing with electrical shock hazards, energized moving parts, sharp metal, and heat stress issues, all while working in a hot, cramped, dark and dirty attic.
Plus it's always best to have a buddy help on this type of repair.
Edited by beam current, 17 August 2014 - 02:09 AM.
I think this will work. I once saw it on a cartoon.
Or, on the other hand.....
Troubleshooting the appliance's complex electro-mechanical systems is the methodology in which one must, by using analyitical techniques and the process of elimination, determine the cause or causes of a specific failure. Rarely does this cause of a failure directly present itself for you to see.
To be better equipped to troubleshoot, you will need:
1.) To follow this: Safety first and foremost. Trust your instincts.
2.) Basic hand tools.
3.) A decent DVOM meter. Buy one. Borrow one. You need one.
4.) Last, but certainty not least, common sense. Most of us have it. Slow down and use it.
Now, let's have some fun!
Hope is the power that gives a person the confidence to step out and try.
Success is the maximum utilization of the ability you have.
It always seems impossible until it's done.