Rooftop A/C Fan Shafts Rusted Off!

87Itasca · March 08, 2016, 01:07 PM

Hi all,

The A/C units on my RV never really worked that well. One blew cooler than the other, so I assumed it was a matter of being low on freon.

Turns out the fan motor shafts that move airflow over the condensers have literalyl rusted in two! The fans are just lying propped up against the condensers. I've never seen anything like this before, can I simply replace the fan motors? Has anyone ever done this? Really not looking forward to replacing both A/C units if not!

87Itasca · March 08, 2016, 01:19 PM

Pics of the carnage...

87Itasca · March 08, 2016, 02:29 PM

I wonder if I could just remove the rust from each side, and make a sleeve that I can screw to both sides of the shaft, and keep on trucking for a while...

legomybago · March 08, 2016, 03:18 PM

You can replace just the fan motor. You can buy them (depending on model #). Take the part #'s off the fan motor and google it. Or just go down to your local RV shop. The only "hard" part was getting the wiring correct. The wires weren't color coded the same in my case, so you have to double check what wire does what

HandyDan · March 08, 2016, 04:08 PM

What brand of AC do you have? Some are easier to work on than others, but replacing a motor isn't very hard. I have done it and I'm not very mechanical.
Just be careful of the big capacitors and be sure to discharge them. Here is a good Youtube video that tells how to swap out a motor:

https://www.youtube.com/watch?v=doJ_oD18lZs

Froggy1936 · March 08, 2016, 05:07 PM

I would not recommend repairing the rusted shaft by any means , If the repair fails the wobbeling fan could do major coil damage , Its time to replace the motor . That is a first to see a shaft rotted off like that & there does not seem to be a lot of rust of screws etc in that area ! Frank

RANGERRICK · March 08, 2016, 07:46 PM

I may have a used motor if you have a part# off the motor or the model# and make of the ac.The ID tag will be mounted on the upper unit or on the under side of the unit.If it is on the under side you will need to remove the two knobs and the two screws that hole the plastic inner ceiling assembly up.Their will be a tag on the bottom of the pan.If you follow the wires to the junction box you may be able to see the color of the wires.

87Itasca · March 10, 2016, 08:03 AM

Hi Rick,

Thank you for the offer, I will try to get up there and see either tomorrow, or over the weekend and let you know. Should you not have one that will work, it seems there are varying types online that I'm sure I could make work just fine. I'd much rather not buy two whole upper/lower units for an RV this old. It won't be used a lot, but A/C is a necessity here in VA, sometimes even in the winter!

ClydesdaleKevin · March 11, 2016, 05:44 PM

Wow! I've never seen that before. I can't imagine road salt could get in there and do that...maybe sea air?

Kev

87Itasca · March 13, 2016, 01:08 PM

There's a photo of the ID tag for you. Hopefully you have something?

It's a three wire fan motor. I see four wire units on amazon, but I'm not sure what the forth wire would have to go to. Could I use a 3.4 vs. 2.8a motor? Not sure if that would trip a 15A breaker when I kicked the AC on.

I really have no idea what caused this. I'd sure like to know though

legomybago · March 14, 2016, 01:38 PM

Quote from: ClydesdaleKevin on March 11, 2016, 05:44 PM
Wow! I've never seen that before. I can't imagine road salt could get in there and do that...maybe sea air?

Kev

That's a good idea Kev, SEA AIR

RANGERRICK · March 14, 2016, 01:48 PM

I got the motor info,i will take a look today.Were you able to get the broken shaft out of the fan blade?

RANGERRICK · March 14, 2016, 05:58 PM

I do have a westinghouse motor that is a two speed and mounts just like yours.Hi speed is only 1625.You can still use your same capacitor.You will not hook up the extra wire.I do have a different make motor with three wires but i do not know any specs on that motor.It would mount to your bracket a little different but will work.

87Itasca · March 15, 2016, 09:01 AM

Hi Rick,

Does it have two "D" shafts? What would you like for it? I'll take it.

RANGERRICK · March 17, 2016, 10:08 AM

Yes,it has two D shafts.It came off of a coleman ac.The cost would be 50.00 plus ship.I see you live in virginia 15-20.00 ??If you have email i can send you some pics of the two different motors.
Thanks
Bill
AKA RANGER RICK

87Itasca · March 17, 2016, 01:05 PM

Sending you a PM Rick.

One of my fan motors came in today, and it looks identical in every way, except it is a 5 wire (red, white, black, brown +ground) whereas my old motor was a 4 wire (red, white, brown, ground). This motor is a two speed, with a red (Lo) and black (Hi) wire. Can I just not connect the low speed wire and cap it off to prevent shorting? Or is there more involved than that?

M & J · March 17, 2016, 05:51 PM

I think his name is Bill.

87Itasca · March 17, 2016, 07:04 PM

A/C #1 IS FIXED!

New fan motor works great! The air coming out of the ducts is freezing! Can't wait to see how well it works on a really hot day. Good old R22!

I just snipped the end off the red wire, stretched the insulation to cover the end, and tucked it aside. Black to red, white to white, and brown to capacitor. Works like a charm.

joanfenn · March 17, 2016, 07:56 PM

RANGERRICK · March 18, 2016, 08:04 PM

I emailed pics of motor i have.

87Itasca · April 05, 2016, 11:49 AM

Just a final update everyone:

I have replaced both of the fan motors, and all is well. RANGERRICK sold me a used one I installed on the front unit, and both are cooling perfectly. Thanks again everyone!

RANGERRICK · April 05, 2016, 06:12 PM

Good job Bill.

87Itasca · April 22, 2016, 09:20 AM

Well, it worked good for a couple weeks, haha.

The motor on the front unit has locked up, and the control board with the sliding switches is HOT. Hopefully I haven't killed the compressor, but I don't know, I don't hear it coming on. I left it on Auto overnight (milder night) to help get rid of some of the humidity in the unit since I had the carpets shampooed. Looks like that might have been a bad idea.

I'm going to be piiiiiiiiiiiissed if I just cooked this thing. One thing after another, I swear.

Hopefully when it cools down, I can switch it on and hear the compressor kick on. If so, hopefully another fan motor is all I need. If not.....I guess it's time for another A/C.

EDIT:

After it cooled off, I hit the switch, and I heard the compressor fire, and the freon start to gurgle. Taking it as a good sign, and going to go ahead and order a replacement NEW motor off Amazon and be done with this.

Rick, I just want to clarify I do not fault you at all. When you sold me the motor, it was indeed functional. It didn't spin as long as the new one, but I had just chalked that up to age. I know you had no way of knowing it was on its way out.

Rickf1985 · April 22, 2016, 10:03 AM

Check the voltage and amperage if you have an Amprobe while running. You may have low voltage getting up there which will give high amperage and cause an overheat. If you do not have an Amprobe then backprobe the AC connections carefully and turn it on and see what the voltage is, watch it as the compressor spools up to make sure it does not drop. If you do have low voltage you may have a bad connection anywhere but I would vote for the connection in the breaker panel.

RANGERRICK · April 25, 2016, 06:27 PM

I am willing to refund your money or send the other motor to you.