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Duo Therm A/C Motor Replacement

Margaret___Bob
Explorer
Explorer
I just replaced the fan Motor and the fan blade and wheel(squirrel cage) on my Duo therm a/c unit. The kit came with a new capacitor.
If I'm reading the instructions correctly the old capacitor(run) stays and the new one gets wired to the old one. I thought at first
I was just replacing the old capacitor.
Anyone else replace their motor and capacitor? Any input would be appreciated. I don't want to damage anything.:?
2003 Wildwood 37BHSS
2012 Dodge Ram 3500 Dually 4x4
9 REPLIES 9

Margaret___Bob
Explorer
Explorer
Well good news. Got to the campground and fired up the a/c and it works fine. Haven't really needed since we've been here but it's nice to know it works.
Thanks everyone for their input!:)
2003 Wildwood 37BHSS
2012 Dodge Ram 3500 Dually 4x4

seaeagle2
Explorer
Explorer
The Start Cap is for start only, there's a relay that only lets it energize during start up. The compressor won't run without the compressor side of the dual run cap hooked up.
2014 F 250 Gasser
2019 Outdoors RV 21RD
"one life, don't blow it", Kona Brewing
"If people concentrated on the really important things in life there'd be a shortage of fishing poles" Doug Larson

JBarca
Nomad II
Nomad II
Hi Bob, OK got it. Good luck with the testing and getting the genny to work...
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

Margaret___Bob
Explorer
Explorer
John...I have every thing ready to test out my a/c unit but now my generator will not start so I can test it and I don't have the time right now to tinker with the generator to get running. I'll have to wait until I get to my campsite tomorrow afternoon to run my a/c.
2003 Wildwood 37BHSS
2012 Dodge Ram 3500 Dually 4x4

JBarca
Nomad II
Nomad II
Hi Bob,

I can read Chris's comment 2 ways, he is correct for the "fan" you only need one capacitor.

However in my case I needed the compressor side of the original capacitor to still work on the compressor. So I used half the old one so to speak.

See here: The wiring diagram off my unit.


You can see for the compressor they have 2 capacitors I believe as part of the hard start kit and mine has that.

Here is the bottom of the original dual capacitor.




The 30 microfarad portion is for the compressor (red wire), the 5 microfarad portion was for the original fan (brown wire).

The new motor and the old motor has brown as the hot side of the capacitor and white as the AC common.


My compressor is blue, red and white. Again white being AC common.


This was the original setup.
The red wire goes to the black hard start capacitor and then from the hard start capacitor the compressor.

The brown went to the fan motor. All the whites jumpered in there are the commons needed to make everything work.

All I did was unplug the brown off the old dual capacitor and plug it onto the the fan 10 microfarad capacitor. And then add a white AC common wire to the new capacitor. Like this


I do not know if the silver can dual capacitor can be eliminated for the compressor. And if the hard start capacitor can cover all the things that the combo it had before. Since mine came that way, I just kept it with 2 capacitors on the compressor. And yes only used 1, capacitor on the fan, the new 10 microfarad.

Does this clear it up?

Hope this helps

John

PS. I had all these pics from way back when as this came up before.
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.

Margaret___Bob
Explorer
Explorer
JBarca wrote:
This may help. I do not know your model but this is my 2004 vintage Duo-Therm 13.5 K BTU unit.

The new motor in place as a big picture of what I have. Note the compressor is removed in this pic.



The new motor next to the old. See the rust on the old motor stator


The tag on the old motor. Used a 5 mfd capacitor.


The tag on the new motor. Needs a 10 mfd capacitor and it came with the motor


In my unit, there is a dual capacitor. Half was needed for the fan the other for the compressor. I still needed the compressor one to work. So I left the dual installed, just unplugged the fan motor leads and put them on the new capacitor. On mine, the new capacitor still fit in the box. See here





Hope this helps

John

Thanks John
You have what I believe is the same exact a/c unit. Mine is from 2002. The only difference that I see is that you wired the brown wire from the fan motor to the new capacitor and the white wire it appears you have going to the old capacitor. My instructions say to "connect the brown and white wires to the remaining terminal on the new fan capacitor". And yes I have to connect the old capacitor to the new one using the 6" jumper wire that came with the new kit.
****Update***John I just read your note on your one photo that you did attach the brown and white motor wires to the new capacitor. Is that correct? The white wire appears to be connected to the old one in your photo. Probably doesn't matter either way.
Thanks,Bob
2003 Wildwood 37BHSS
2012 Dodge Ram 3500 Dually 4x4

Margaret___Bob
Explorer
Explorer
Chris Bryant wrote:
The new capacitor will replace the old one. You want only 1 in the circuit.

Chris...my instructions show a 6" jumper supplied with the the new motor that connects the old capacitor to the new. John posted photos of his after installing the new capacitor showing what I'm instructed to do. Which leaves me with a total of 3. The third being the start capacitor.
I originally thought that I was replacing the old one until I read the instructions.
I would have posted a photo of my instructions showing the connection but I'm not sure how too. Something with the URL
2003 Wildwood 37BHSS
2012 Dodge Ram 3500 Dually 4x4

Chris_Bryant
Explorer
Explorer
The new capacitor will replace the old one. You want only 1 in the circuit.
-- Chris Bryant

JBarca
Nomad II
Nomad II
This may help. I do not know your model but this is my 2004 vintage Duo-Therm 13.5 K BTU unit.

The new motor in place as a big picture of what I have. Note the compressor is removed in this pic.



The new motor next to the old. See the rust on the old motor stator


The tag on the old motor. Used a 5 mfd capacitor.


The tag on the new motor. Needs a 10 mfd capacitor and it came with the motor


In my unit, there is a dual capacitor. Half was needed for the fan the other for the compressor. I still needed the compressor one to work. So I left the dual installed, just unplugged the fan motor leads and put them on the new capacitor. On mine, the new capacitor still fit in the box. See here





Hope this helps

John
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.