AC/Blower fan makes loud bang noise

[CF542]

I have had a strange issue happening with a loud bang noise coming from the ceiling blower inside the AC unit.

I first heard this noise last summer on a hot day where the unit had been working for several hours. The sound itself sounds like someone slamming the front door of the RV. There is no malfunction associated with it afterwards but it is a very loud noise.
Several seconds before the noise, the fan makes a whistling noise as if the airflow is somehow being restricted. After the bang, the unit continues and the sound may come back or may not. I assumed it may be the AC unit, however on a cold day where the heater was on along with the blower, it happened again. There is no consistency in the event.
I took it to my RV dealer however they had not heard of this and could not reproduce it in the time they had it.

Has anyone experienced this as well?

[howson]

I have had a strange issue happening with a loud bang noise coming from the ceiling blower inside the AC unit.

I first heard this noise last summer on a hot day where the unit had been working for several hours. The sound itself sounds like someone slamming the front door of the RV. There is no malfunction associated with it afterwards but it is a very loud noise.
Several seconds before the noise, the fan makes a whistling noise as if the airflow is somehow being restricted. After the bang, the unit continues and the sound may come back or may not. I assumed it may be the AC unit, however on a cold day where the heater was on along with the blower, it happened again. There is no consistency in the event.
I took it to my RV dealer however they had not heard of this and could not reproduce it in the time they had it.

Has anyone experienced this as well?

I think the question you asked in the other thread https://gdrvowners.com/forum/operati...781#post128781 (and my response) has already answered your question?

Feel free to use this thread for further questions, clarification, (and hopefully) documenting what you find.

[CF542]

Thanks for the reply. I was wondering if there was a specific procedure I should follow or if there were torque specs for these bolts if they are loose.

[howson]

Thanks for the reply. I was wondering if there was a specific procedure I should follow or if there were torque specs for these bolts if they are loose.

No specific torque value I'm aware of on the fan motor screw -- "good 'n' tight" should work.

There are multiple YouTube videos posted by various individuals that work through the process of replacing an air conditioner fan motor. The inspection process will be similar. I did a search for fan motor replacement coleman rv air conditioner and there were dozens of related videos.

The most important aspects I can think of (may not be exhaustive) are: 1) safely working on the roof -- falling off will be the start of a bad day; 2) electrical safety. Even with all power removed the camper, the start and run capacitors may still hold a charge. Finally, the only other thing I can think of is the fins on the coils are extremely sharp. Easy to slice open unprotected skin.

Other than that...it's a relatively simple task with basic DIY'er skills to remove the a/c shroud and inspect the interior.

If any of the above cautions make you pause, consider hiring an RV mobile mechanic to do the inspection. If you're at a campground, consult the front desk for a reputable mechanic in the area.

Hiring someone is not inexpensive, but it will cost way less than a trip to the ER.

Howard

[Scott'n'Wendy]

No specific torque value I'm aware of on the fan motor screw -- "good 'n' tight" should work.

At work we used to say "good'n'tight.....but don't break it"