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gotoman for ac, HVAC Technician
Category: HVAC
Satisfied Customers: 5052
Experience:  51 years of experience install design and repair of all makes and models of AC
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Came home, outside a/c unit running. Inside was not, house

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Came home, outside a/c unit running. Inside was not, house was warm. Air handler coils froze up, fan not running. Fan turns freely by hand (power off). Meter on R and C gets 28 volts. Jump R and G and get nothing. Now what?

Wvfan79 :

Hello there! I'm Norman but you can call me Norm. Let's see what I can do to get you some answers today. I'm ready to get started whenever you are.

Wvfan79 :

Hope you are doing well today.

Customer:

I am ready

Customer:

I am fine, you?

Wvfan79 :

If you look in your air handler you should see the wires that lead from the board to the blower motor. Depending on your model you may see wires connected to the board at terminals labeled COOL, HEAT, PARK, COMMON (C). If you can locate these connections you can check from the White Common (C) wire of the blower to the COOL tap while calling for A/C when the outdoor unit is running and you should get voltage. Are you able to check this now?

Wvfan79 :

I'm great!

Customer:

Let me turn on the ac

Wvfan79 :

ok

Customer:

Waiting for it to call for cooling...will that be a/c voltage

Wvfan79 :

Yes

Wvfan79 :

I may need your air handler model number to guide you better once you get in there.

Wvfan79 :

Depending on age and series the setup will be different. Some have control boards others just have fan relays, etc.

Wvfan79 :

We just need to confirm if the blower is getting line voltage.

Customer:

I found the white wire but don't see park, cool etc

Wvfan79 :

How many wires go to the blower?

Wvfan79 :

and colors

Customer:

looks like about 3 or 4 in one clip and then another clip with about 12

Wvfan79 :

Let me get your model number. Should be on the cabinet.

Customer:

fk4cnf003

Customer:

coils icing up

Wvfan79 :

The problem is that the blower isn't running. Shut it down for now.

Wvfan79 :

Give me one second to pull a couple items together.

Customer:

Ok.

Wvfan79 :

Ok, sorry it took so long.

Customer:

No problem

Wvfan79 :

This air handler has what Carrier calls their ICM motor, Variable speed.

Wvfan79 :

This isn

Wvfan79 :

This isn't going to have the normal wiring and it's DC voltage not AC votlage. To test the motor and find if it's a icm module or a motor you'd want to have the proper motor testing tool. Without it you could spend lots of money replacing the wrong item.

Customer:

Ok. Is there a way to get it running so it will stay on until tomorrow..kind of warm here in Florida at the moment.

Wvfan79 :

There are ways to pull the harness and jump out the plug but I'm not comfortable guiding you in that. The jumps can test the operation and help to narrow down the problem. I would like to opt out and allow another expert to step in if one is available and versed in this product. I'm very sorry.

Customer:

Ok....if this is a big undertaking, I am not real interested in zapping myself or starting a fire, lol. Should I just wait and call somebody in the am?

Wvfan79 :

Diagnosing a variable speed motor can be tricky but old Carrier techs on here may have some short cuts and simple test for you. I'm sorry to have delayed your request. Please remember to hold your final rating for the answering expert. Please stand by and if someone is able to help they will jump in.

Customer:

Ok, thanks for your help. Have a good night.

Wvfan79 :

Best of luck my friend! Have a great night.

Russ here.. Not much you can do tonight. Jumper wrong pin will damage the fan board. 98% of time it is the module. This is not customer friendly model. To prevent damage to components best left to service tech. Sorry Russ
Customer: replied 3 years ago.

Ok, thanks. The page where I could rate the service is gone. Now what?

I will send one more time. Russ

gotoman for ac, HVAC Technician
Category: HVAC
Satisfied Customers: 5052
Experience: 51 years of experience install design and repair of all makes and models of AC
gotoman for ac and other HVAC Specialists are ready to help you

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