Air Conditioner Fan Binding/Stopping

[Mr. Adventure]

Given the clamp that holds the blower on the motor shaft in the Norcold 9300 series AC, I'm absolutely sure we aren't the only ones with this problem. But surprisingly, I couldn't find anything on this in the forum or on the Internet either (maybe I was using the wrong search terms).

I've been dealing with this one for a couple years, where the AC blower would run for awhile, but eventually grind to a scraping stop. I could usually get it running again by removing the filter and reaching up with my left hand and pushing the blower up a bit (don't try this with the switch on). But this season, the AC blower would come to a hard stop in less than 5 minutes.

Yesterday I climbed up there and fixed the problem:

- Remove the AC cover
- Watch out for all those sharp sheet metal edges in there!
- Remove the aluminum sealing tape around the top of the blower housing.
- Pull all the sheet metal screws around the top of the blower housing (motor can remain attached).
- Carefully lift the motor and sheet metal top and turn it over.
- Loosen the clamp the holds the blower on the motor shaft, push the blower back to where it lines up with the end of the shaft, and re-tighten the clamp.
- put it all back together, taking care to use the right screws in the right places.

The bottom line:
- 20 minutes to take it apart
- 5 minutes to fix it
- 20 minutes to put it back together
- Plus: About two hours to drill out the stainless steel AC cover bolt that spun aimlessly instead of unscrewing, going to the hardware store to get a new bolt, a tap for the new hole to screw it into, and aluminum tape to re-cover the joints in the housing.

So I managed to make a half day project out of this, but still less than the time it would have taken to to haul the TM to an RV repair shop and then go back to pick it up again in a day or two.

[Craigrrr]

I just tried my AC for the first time today, blower fan seems to be jammed , I can barley turn it , must have been like that for awhile as some of the fins on the blower wheel are broken as if someone tried to turn it and could not. I guess I will pull mine apart tomorrow and see if this will correct it.

[Craigrrr]

I took the shroud off today to chk if the blower wheel has slipped down making unit hard to turn and fan blower just hum. Found it was a bad fan capacitor and fan blade was jammed with debri inside the shroud full of tree needles and leaves and dirt. etc... cleaned it up . Replaced the capacitor now she blows cold air and warm air, as it does have a heat strip installed.

Not bad for a $3.42 fix. New cap in box, old cap on the right

[ArkyDoodle]

How did you determine that the capacitor was the problem? I assume the replacement was easily obtainable from a local RV parts supplier?

[Craigrrr]

Arkydoodle, The fan motor would hum , so from there I went to chk the fan capacitor with my ohm meter, it was open . I picked up the capacitor from a local appliance repair parts store, MUCH cheaper price. Plus I used to own an appliance repair shop. So I knew what to look for and get a good price.



To chk with a multi meter, first make sure you have the power off, then use an insulated screwdriver and short across the terminals of the capacitor in question. Then disconnect the wires and place your meter in the rx1 ohm scale setting touch the meter leads to the capacitor terminals , the meter needle should go up then go back down. if not the cap. is bad . You can also chk the microfarads with a digital meter as well. but really not needed if you find an open cap.

[Padgett]

Well for a basic meter, HF has these as freebies often (is one now, click on the Print Coupons at the top of the page.

If you want something more serious then the most cost effective I've found is the Mastech MS2108A has a clamp-on DC current measurement, Capacitance measurement, and a peak hold, unusual in something under $50.