Air Conditioner Fan Problem

[jamesp]

We haven't used our unit since late last summer (busy building a house) and just now got through kid's activities and are preparing for a trip. I plugged the camper into the 30 amp service and went inside to turn on the AC. When I turned it on, I heard the ac kick in but no fan. I tried that several time and the fan never came on. I went to the roof with tools in hand. Took the cover off and faught wasps for a few minutes. I checked to see if the fan would spin freely. I seemed stiff but then started spinning freely. I went back down and kick on the AC and the fan started and all seems fine. I'm struggling trying to figure out why it wouldn't start by itself. I guess we will see how it goes over this trip.

[LadyWindrider]

I wouldn't worry too much. The motor probably has a steel shaft running through brass bushings instead of bearings. A little rust or corrosion probably built on the shaft, and the motor was not strong enough to break it free. Now that you have done that, it should be fine till the next long period of non use anyway.

[msula95]

I had the same problem when I got going this spring. I went up top, removed the AC cover and spum the fan. It resisted minimally, but that took care of it.

Now that I've jinxed myself, we leave this morning for a 5 day trip with temp.s in the 80's-90's.

[jamesp]

I actually found this article this morning about AC maintenance. It looks pretty easy and makes a lot of sense to me. I'm going to look for the oil tubes but a little 3 in 1 oil on each end of the shaft should help prevent it again. I think I will do the coils when I return. I'm pulling out in a little while and low 90's are expected in TN this weekend.

RV AC And Camper Rooftop Air Conditioner Maintenance and Repairs

[tomjsas]

great link...thanks for posting it.

[KyDan]

3 in 1 oil and WD 40 both evaporate in just a few weeks.
Much better is a drop of plain old engine oil.
Yeah, 10 w 30 or something like that.
What ever you have in the garage.
It will last years.

[jamesp]

Good idea on the motor oil instead of 3 in 1 oil. The AC is working fine. When we return, I'm going to buy the cleaner that is in the attached link and give it a try on the coil fins. I'm also going to vacuum everything off and oil the motor shafts. The can of cleaner has good responses from users and should get a couple uses from one can.

AC-Safe Air Conditioning Coil Foaming Cleaner - AC-920 at The Home Depot

[RJHuser]

You're right, WD40 is not a lubrication oil, it is primarily a solvent with a small amount of lubrication properties.

3-IN-1 Oil, however, is a lubrication oil with a small amount of solvent properties (it is also classified as "sewing machine oils"). It is about a 10 weight oil. It will not evaporate any more than any other motor oil, what does evaporate is the little bit of solvent material in the oil, leaving behind the lubrication oil component.

It is great for small motors such as fans in air conditioners. It's low viscosity allows it to flow easily into the tight clearances of bronze bushings (bearings) used in these types of motors. Its low amount of solvent properties allow it to penetrate gummed up bushings in these motors and get the lubrication component into the bearing.

They also make 3-IN-1 Motor Oil. Its basically the same as 3-IN-1 Oil except it is about a 20 weight oil.

(I'm not an oil or air conditioner expert, just an engineer and mechanic).

Rick.

[KyDan]

Many years ago I used to shoot black powder guns.
I have several hanging on the wall yet today.
After an afternoon at the range I'd have the odorous job of cleaning
them. Black powder leaves a messy sulfurous residue in and on the guns.
Most folks cleaned their guns or at least some parts of the gun with
soapy hot water. Me too.

After cleaning you have to thoroughly dry and oil the gun to prevent rust.
Many times I wiped the gun inside and out with 3 in 1 oil.
I can tell you that after hanging on the wall for 6 months a gun that
was positively shiny and oily to the touch will be dry.
3 in 1 oil evaporates over time.
Now that I no longer shoot them on a regular basis I use motor oil in the
bore when I take them off the wall once every few years to dust and re-clean
them.

You probably won't hurt your electric motor by using 3 in 1 oil but
if you're going to that much trouble why not use motor oil and forget it?

My previous home AC/heat pump had oil caps on the fan motor.
I think it was the inside air handler but memory dims over time.....
it said specifically NOT to use "sewing machine oil".

I'll modify my statement...... all oil will evaporate eventually.
The lighter the oil the faster the evaporation.
I keep an oil can in the garage with engine oil in it.

My 2¢