Go Back   iRV2 Forums > TRAVEL TRAILER, 5th WHEEL & TRUCK CAMPER FORUMS > 5th Wheel Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 08-21-2008, 07:32 AM   #1
Junior Member
Join Date: Aug 2008
Posts: 2
I have a roof mounted a/c unit and all it does is hum. Any suggestions?

momike is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 08-21-2008, 07:32 AM   #2
Junior Member
Join Date: Aug 2008
Posts: 2
I have a roof mounted a/c unit and all it does is hum. Any suggestions?

momike is offline   Reply With Quote
Old 08-21-2008, 07:45 AM   #3
Junior Member
Join Date: Aug 2008
Posts: 1
momike if it sounds like the compressor is humming. I think your fan capasitor is no good if your a/c is a coleman. If it's a dometic see if you can turn the fan could be froze up. This will hape if not used too much.
G&Nmobilervrepair is offline   Reply With Quote
Old 08-21-2008, 07:52 AM   #4
Moderator Emeritus
TXiceman's Avatar

Vintage RV Owners Club
Texas Boomers Club
Oklahoma Boomers Club
Ford Super Duty Owner
Join Date: Aug 2000
Location: Full Time, TX Home Base
Posts: 17,169
Blog Entries: 21
Howdy and welcome to iRV2.com.

Do you know if the compressor is running or not? If the hum is the compressor running and the fan does enot run, you may have a bad start capacitor on the fan motor or a bad fan motor.

With the A/C off and preferrably with the A/C breaker in the OFF position, remove the outside cover from the unit. Now, see if the condenser fan motor will move easily. If it rotates easily, have some one turn on the A/C breaker and stand by the A/C thermostat. Spin the fan by hand and tell them to turn on the A/C unit.

BE VERY CAREFUL around the open and exposed fan.

If the unit then runs normally, you probably have a bad fan capacitor, which can be found at some hardwear stores and A/C supply houses.

Be sure and kill the power to the u nit and short the terminals on the capacitor to drain the charge and not shock yourself.

Amateur Radio Operator (KE5DFR)|Full-Time! - 2012 6.7L Ford Crew Cab Dually -2013 HitchHiker Champagne 38RLRSB - Travel with one Standard Schnauzer and one small Timneh African Gray Parrot
TXiceman is offline   Reply With Quote
Old 08-21-2008, 08:29 AM   #5
Senior Member
Frank P. Martin's Avatar
Pond Piggies Club
Mid Atlantic Campers
Join Date: Jan 2000
Location: Fayette Ridges of PA, USA
Posts: 998
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> ... all it does is hum. </div></BLOCKQUOTE>

What's the name of the tune your A/C unit hums?

You don't say whether your unit is blowing any air. If there is no airflow, it's possibly a problem with the fan and/or motor that drives it.

I have a Coleman Mach III A/C unit and I don't use it very often. I had a problem once where my fan wasn't turning. I was able to reach the inside fan by removing the return air grille/filter in the ceiling and then removing the screws that hold the metal plate covering the main cold air duct. Once removed, I could see the fan. I reached in there (with the unit turned off, naturally) and tried to move the fan. It was real stiff (most likely from lack of use), but as I kept moving it, it turned easier and easier. Once it felt pretty loose, I tried starting the unit and the fan began working again. I put everything back together and it's worked OK ever since.
2009 GMC Sierra 2500HD | Crew Cab | Standard Box | 4WD | Duramax/Allison
2000 Jayco Eagle 266 | FBS | TT
1986 Coleman Laramie pop-up -- Still in the family!!!
Frank P. Martin is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
HWH Jacks working, not working and working again? Bob&Pat Winnebago Industries Owner's Forum 6 06-08-2006 04:22 AM
Working way south Windy Camping Locations, Plans & Trip Reports 1 01-03-2006 03:33 PM
Working out the bugs. resqguy Winnebago Industries Owner's Forum 9 10-27-2005 05:30 PM

» Featured Campgrounds

Reviews provided by

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:57 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.