Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > THE OWNER'S CORNER FORUMS > National RV Owner's Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Thread Tools Search this Thread Display Modes
Old 01-17-2022, 03:15 PM   #1
Join Date: Apr 2010
Posts: 46
2005 National Tropical Dash A/C

When I turn the dash selector switch from defrost to any of the other 3 positions i.e. defrost and feet, feet and chest, the unit will not redirect the heat from anything other than defrost. Looking under the dash there is a solenoid type pod with a push rod to the activator deflector that I can move manually to change the direction of flow. Subsequently there is a 2nd pod solenoid that when activated directs heat to the drivers feet i.e. floor. Neither of these units are working. Are they vacuum operated. It cant be a fuse because they did switch once in the last month when the dash selector was adjusted, hence it shouldnt be a fuse. Can it be a problem with the dash selector switch itself. Its hard to see or feel with the in dash radio in position. Your thoughts please. Where do I go from here? Keith
2000 National Tradewinds Class A Motorhome
rkscott is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! 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 01-17-2022, 03:22 PM   #2
Senior Member

Holiday Rambler Owners Club
Join Date: Aug 2015
Posts: 5,918

The symptom- nothing in any position other than defrost- points to a vacuum leak. If your coach is a rear-engine diesel, it should have a vacuum pump. Find it, and look for broken tubing starting there. If yours is a gas coach, it may have a vacuum reservoir. Some reservoirs are spherical, some more rectangular. Find it and look for broken tubing starting there. It's more likely the tubing is broken on the front side of the firewall, rather than inside the dash.
2008 Holiday Rambler Admiral 30PDD (Ford F-53 chassis)
2009 Honda Fit Sport
l1v3fr33ord1 is offline   Reply With Quote
Old 01-17-2022, 04:18 PM   #3
Senior Member
Ken C's Avatar
Join Date: Nov 2007
Location: Fulltime, Formally SF Bay Area
Posts: 584
We had 3 previous National Diesel motorhomes and all three had a vacuum pump mounted to the outside of the firewall in on the drivers side. I would first check and see if the vacuum line from the pump is in good condition as well as check to see if the pump functions with the key in the run position. There is also a door on the outside that opens and closes which whether the air recirculates or allows outside air in. I seem to recall a small vacuum tank in the same area as well but it has been a number of years since we owned a NRV coach.
Ken C
2018 Dutch Star 4052 Spartan
2015 Jeep Cherokee Trailhawk
Ken C is offline   Reply With Quote
Old 01-25-2022, 06:58 PM   #4
Senior Member
Join Date: Nov 2015
Location: EAST TN
Posts: 186
dash vents

if diesel, after the coach sits overnight, get someone inside to turn the ing key to the on postion while you are outside in front (away from the buzzers) and listen for the electric vac pump to pull vac and shut off. vac pumps are somewhat noisy.

if pump not running, fix that. if pump running and will not quit running,vac leak somewhere fix that. if pump ran and then stops (vac is pulled) then move dash control , listen for vent (door) to move or maybe hear vac leak.
If all else fails the (door) may be stuck even with vac on it. Yes, fix that.
The vac system works sorta like a air system in reverse. It uses vac to move stuff instead of air pressure.

good luck
10EC is offline   Reply With Quote
Old 01-25-2022, 07:35 PM   #5
Join Date: Jun 2013
Posts: 59
I had the same problem on my 2003 Dolphin. Turns out, i knocked a vacuum hose loose when adding coolant to the overflow reservoir. Look for a ball type device about the size of a softball in the engine compartment with a couple of small hoses. See if any hoses are off.
fitzjohnfan is offline   Reply With Quote

national, dash

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
national tropical 396 :: 2005 national tropical 396 cricket2386 iRV2 Owners Registry 1 07-30-2021 12:15 PM

» Featured Campgrounds

Reviews provided by

All times are GMT -6. The time now is 04:50 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.