My A/C system is 17 years old and for the first time the condenser fan stopped working. So I thought it would be the motor so I replaced both the motor and the capacitor at the same specifications. Turns out I'm still having the same problem. The fan will start when I first turn everything on but dies 5 min later and I can repeat the process over and over but fan won't stay on as it's supposed to. I'm dumbfounded right now and don't know what else to look for.

First off is the motor real hot when it shuts down? Please turn power off before you test this! Next is the compressor turning off at the same time as the fan? The reason I ask this is because a low or high pressure switch could also be causing this.

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Originally Posted by hvac1000

First off is the motor real hot when it shuts down? Please turn power off before you test this! Next is the compressor turning off at the same time as the fan? The reason I ask this is because a low or high pressure switch could also be causing this.

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The compressor stays on but the fan turns off. The fan motor is functioning normally. It seems as if the dual capacitor is running in the start phase until it drains all the power out then as it switches to the run phase there's no power to keep the fan running. My guess would be the contacter.. :confused:

If the compressor stays running the contactor is working OK. I would suspect on of three things. The replacement motor is not of the same speed or horse power rate as the original. The fan blade if replaced is not of the same pitch as the original. The motor is wired incorrectly or the capacitor is defective or both.

You did not answer the question as to weather the fan motor is real hot when it shuts off?

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Originally Posted by hvac1000

You did not answer the question as to weather the fan motor is real hot when it shuts off?

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Sorry I didn't answer the first time. I just recently checked the temperature after turning off and wow, I almost burnt some skin off. It got very hot. Is the capacitor causing this?

The capacitor could be causing it and I would suggest you rep0lace it with the proper one for the motor. The correct capacitor mfd. Number is located on the label on the motor. You might have to take the motor back out to dee this. Also while you are in there check to make sure the horsepower rate is the same as the old one.

One last item I hope the motor is running in the correct rotation.

The horsepower isn't exactly the same. The guy who sold it said it's OK.. so I took his advice.

Old motor specs:
HP 1/8
Rpm 1100
Amps .90
Cap 5.00/370

New motor specs:
HP 1/6
1075
Amps 1.0
Cap 5/370

Plus the capacitor I'm using is a dual capacitor 35+5mfd/370volt. I get the same symptoms when I have the old motor or new motor installed. I'll go back to the store and see if they can exchange the capacitor.

Went to the store and they did a test on the capacitor. Turns out it was defective.. new part comes in tomorrow so I'll give an update after putting the new part in.

Sounds good to me. You learned a lesson on this. Always replace the capacitor when replacing a motor or compressor.

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Originally Posted by hvac1000

Sounds good to me. You learned a lesson on this. Always replace the capacitor when replacing a motor or compressor.

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Well, I went back to the store and turns out that the capacitor wasn't even defective... the person who was testing it didn't know how to use the equipment correctly and claimed it as defective. But I still made the switch with another capacitor just in case. So I installed the replacement but I still have the same problem.. any ideas?

The only thing else I can think of is if it is wired incorrecty. You should recheck the wiring diagram on the motor<<<<< and make sure that is how it is wired.

I'd say it has to be wired wrong. What wires do you have hooked where? You should have 1 wire that goes to the capacitor, and two that go to the contactor, sometimes you will have a high and a low speed, in this case one will need to be capped off.

My old motor had 3 wires, and new motor 4 wires. The only part I was skeptic was on the brown and brown+wht stripe wires. I connected the brown wire to the capacitor to where it said fan and also the brown+stripe at the same spot where it says fan... is that correct? The capacitor I have is a dual capacitor... has herm, com, and fan.

Both brown wires can't go to the dual capacitor, unhook and cap off the brown wire with the white stripe, it should work.

Just wanted to let you guys know that I fixed up the problem! I pulled the brown+wht stripe wire from the capacitor and everything worked as it should. Thanks for the help!