|
09-12-2014, 11:52 AM
|
#1
|
Rivet Loser
La Ronge
, Saskatchewan
Join Date: Nov 2011
Posts: 328
|
HVAC problems
I have a 1994 Land Yacht Legacy 34. At the beginning of a day's drive, the heater and AC seem to work just fine. As the miles and the day wsears on, and especially if we're doing multi day trips, the amount of air coming out gets less and less, down to zero/zilch/nada, I can still hear the fan blowing though. This seems to be a distribution problem, because there is both cool AC air and hot air at the start of any day.
I should emphasize that I am talking about the dash air and heat.
|
|
|
09-12-2014, 12:04 PM
|
#2
|
Rivet Master
Airstream Dealer
Corona
, California
Join Date: Feb 2002
Posts: 16,497
|
Quote:
Originally Posted by Punch
I have a 1994 Land Yacht Legacy 34. At the beginning of a day's drive, the heater and AC seem to work just fine. As the miles and the day wsears on, and especially if we're doing multi day trips, the amount of air coming out gets less and less, down to zero/zilch/nada, I can still hear the fan blowing though. This seems to be a distribution problem, because there is both cool AC air and hot air at the start of any day.
I should emphasize that I am talking about the dash air and heat.
|
Your describing a freeze up situation.
As you dash air keeps working, it's slowly building up some ice that gets in the way of the air.
The usual problem is a dirty air filter, as not enough air is crossing the cooling coils.
Andy
|
|
|
09-12-2014, 12:35 PM
|
#3
|
Moderator
2017 26' Flying Cloud
Alamo Heights
, Texas
Join Date: Aug 2006
Posts: 8,500
|
Another problem that can cause the evaporator coil to freeze up on longer trips is low refrigerant levels.
__________________
— David
Zero Gravitas — 2017 Flying Cloud 26U | WBCCI# 15566
He has all of the virtues I dislike and none of the vices I admire. — Sir Winston Churchill
|
|
|
09-12-2014, 12:59 PM
|
#4
|
Rivet Loser
La Ronge
, Saskatchewan
Join Date: Nov 2011
Posts: 328
|
Thanks both. But this occurs if the AC is off and I'm just on heat too. Woould I still get freeze up?
Andy...... air filter? What air filter?
|
|
|
09-12-2014, 02:03 PM
|
#5
|
Moderator
2017 26' Flying Cloud
Alamo Heights
, Texas
Join Date: Aug 2006
Posts: 8,500
|
So, you don't get air output from ANY vents (floor, dash, windshield) when this is happening, but you're sure the fan is still turning at normal speeds? Depending on how the distribution is controlled, it might be a servo problem but I'd expect the air to always go SOMEWHERE, the distribution controls should affect where, but not be able to turn it off (in most automotive systems... I've no experience with the moho system specifically.)
__________________
— David
Zero Gravitas — 2017 Flying Cloud 26U | WBCCI# 15566
He has all of the virtues I dislike and none of the vices I admire. — Sir Winston Churchill
|
|
|
09-12-2014, 02:05 PM
|
#6
|
Rivet Master
1974 Argosy 20
2014 20' Flying Cloud
Kooskia
, Idaho
Join Date: Jul 2009
Posts: 4,591
|
Quote:
Originally Posted by Punch
Thanks both. But this occurs if the AC is off and I'm just on heat too. Woould I still get freeze up?
Andy...... air filter? What air filter?
|
Yes, because the air first goes through the cooling part of the system to dehumidify it, then to the heater section to warm it up so it is warm and dry. So, freeze up can happen even when using heat.
|
|
|
09-12-2014, 05:11 PM
|
#7
|
Rivet Loser
La Ronge
, Saskatchewan
Join Date: Nov 2011
Posts: 328
|
Thanks David and idroba.... I can still hear the fan blowing away, but I don't get air coming out, at least not to feet and face, although I'm not sure about windshield. At first, at the beginning of a run, all is normal, but then after a while, maybe an hour or two, I have to move the control to Max in order to get flow, then that slows and eventually all air flow seems to stop, but I can still hear the fan blowing somewhere just as strongly.
Thaks for the clarification, idroba. I guess I need to find where the air filter is.... under hood or in front of passenger seat maybe?
=====
Edit: this thread
http://forums.trailerlife.com/Index....d/25390449.cfm
..... seems to indicate that the consensus is there is no such thing as a dash air filter?
=====
My initial thought was whether I had some kind of progressive vacuum leak that for some reason got worse over time, but then disappeared by a new day, something heating up then leaking? I have no idea what I'm talking aboput though.
|
|
|
09-12-2014, 05:24 PM
|
#8
|
Rivet Master
1974 Argosy 20
2014 20' Flying Cloud
Kooskia
, Idaho
Join Date: Jul 2009
Posts: 4,591
|
I am pretty sure your coils are freezing up. When it happens again, try turning the system off for a while (maybe half hour) and then re starting it. If it now blows air, what has happened is that the coils unfroze and air flow is resumed.
You probably will need service. The possibilities are low refrigerant or a defective pressure control which does not shut the compressor down at the right temperature. There are no air filters in the old system you have which would cause the problem.
Most AC repair shops will understand what is going on if you explain it to them, and will be able to find the issue. It is pretty common. Even my 2012 Jeep Grand Cherokee has the issue now and then, and I need to have the thing repaired under warrantee.
|
|
|
09-12-2014, 05:39 PM
|
#9
|
Rivet Loser
La Ronge
, Saskatchewan
Join Date: Nov 2011
Posts: 328
|
Thanks idroba, I shall take it to a different shop than the last one, since they couldn't find why my heater wasn't working, and I then found it was because the cable had disconnected at the dash control end! The trouble is finding someone competent and honest.
|
|
|
09-14-2014, 05:31 PM
|
#10
|
3 Rivet Member
2000 31' Excella
Ontario
, Canada
Join Date: Feb 2010
Posts: 215
|
You have to appreciate this guy!
Quote:
Originally Posted by Inland RV Center, In
Your describing a freeze up situation.
As you dash air keeps working, it's slowly building up some ice that gets in the way of the air.
The usual problem is a dirty air filter, as not enough air is crossing the cooling coils.
Andy
|
Hi Andy. It is so good to see your input on the Airstream Forums. I have owned 3 a/s trailers and now a LY 30 M/H. Your inut has always been most valuble and appreciated over the last 15 years. Thank you and keep the info coming.
Woodytwo
|
|
|
09-21-2014, 09:22 PM
|
#11
|
Rivet Master
1994 36' Classic 36 Diesel
Colorado Springs
, Colorado
Join Date: Mar 2012
Posts: 883
|
Had a similar problem in my classic, and affected both heating and cooling. It turned out to be a bad grounding cable for the dash fan. Specifically, the gauge wire was too small for the ground, it would get very hot, and over time the thermal buildup would kill the voltage to the motor and therefore the airflow, but the fan still sounded like it was running. Recommend checking your grounding wire. If it is an 18-14 gauge wire, recommend changing to an eight to ten gauge.
__________________
1994 36' Classic Diesel Pusher
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|