kathybug
New Member
We have a 2006 Aspect Class C with a e450 engine. We are only getting cool air when there is no exceleration on the gad peddle. Is this normal?
Dash Air Conditioner 2006 Aspect Class C
- Thread starter kathybug
- Start date
Morich
Senior Member
Should be no difference in the air conditioner temperature when the engine speed changes. Are you saying the air seems colder when the engine is running faster?
There might be several things that might cause this, but we need to know what you are seeing before we try too many guesses!
Does the air come out different vents like at the floor or on the windshield when you try changing that setting?
Do you feel the air blowing out different places as you change the heater from floor to other vents or the windsheild?
What I am thinking is that it might be some of the vacuum lines that control the vents and valves that change which door are open to send the air different places.
But the main idea may be that this is likely to be more of a truck chassis problem than an RV problem! they buy a "stripped chassis from the truck builder and then build the RV on top. That means we need to look for info from the folks who built the truck part when we talk about things like the dash air conditioner.
We get lots of online info about the RV but not much at all about the engine and chassis parts, so we are not too good unless we happen to have one to look at!
There might be several things that might cause this, but we need to know what you are seeing before we try too many guesses!
Does the air come out different vents like at the floor or on the windshield when you try changing that setting?
Do you feel the air blowing out different places as you change the heater from floor to other vents or the windsheild?
What I am thinking is that it might be some of the vacuum lines that control the vents and valves that change which door are open to send the air different places.
But the main idea may be that this is likely to be more of a truck chassis problem than an RV problem! they buy a "stripped chassis from the truck builder and then build the RV on top. That means we need to look for info from the folks who built the truck part when we talk about things like the dash air conditioner.
We get lots of online info about the RV but not much at all about the engine and chassis parts, so we are not too good unless we happen to have one to look at!
creativepart
Senior Member
Site Team
RV LIFE Pro
Your 2006 Aspect Class C is basically a Ford pickup truck. So an auto A/C repair shop should be able to diagnose the issue for you. Find a truck A/C repair shop and let them look at it.
Wait, some older. Class C’s were Ford chassis and some were Chevy (Workhorse) chassis. So I don’t know enough to know what you have. But regardless it’s an automotive A/C system.
So, I checked the 2006 Aspect brochure and see there were only Ford chassis - E350 and E450.
Wait, some older. Class C’s were Ford chassis and some were Chevy (Workhorse) chassis. So I don’t know enough to know what you have. But regardless it’s an automotive A/C system.
So, I checked the 2006 Aspect brochure and see there were only Ford chassis - E350 and E450.
Last edited:
creativepart
Senior Member
Site Team
RV LIFE Pro
Many vehicles have a clutch on the A/C compressor that uses engine vacuum to reduce the HP hit on the engine from the compressor when under heavy load. That’s not unusual, but it shouldn’t be all that noticeable or a problem unless there is a malfunction in that system.
Morich
Senior Member
If you want to do a bit of easy looking for a cause, it may be as simple as looking at the small vacuum lines under the hood.
This is certainly not the only thing that can go wrong but if I remember that engine and controls correctly, there will be a bunch of vacuum lines about a 1/4 inch wide that run from many of the controls to small valves that move different flaps in the heat and air unit. As those flaps move it does all kinds of things like move flaps to different positions to direct flow up to the windshield, down to side vents, or to the floor.
If those flaps don't move in the right way, the whole things may do odd things!
Things like the valve which cuts off hot water flowing through the unit may not move and you can wind up with both heat and air conditioning being done at the same time and that sounds like what you may be telling us??
A simple look at those small vacuum lines may show them to be old, dry, and brittle. If you bend them and see cracks, there is a good chance it is time to change those tubes as they often get cracks that leak vacuum at times when there is not a large vacuum being provided by fast engine speeds!
Usually not a high tech, complex thing as they often are just stuck on the fittings and can be pulled off and the tubing is very common and pretty cheap to replace.
If you want to DIY, this might be a cheap, simple thing to do as a starter?
One point to be careful on is that the plastic fitting can also get brittle as they age, so a bit of gentle is good to avoid breaking the end off the fittings!
This is certainly not the only thing that can go wrong but if I remember that engine and controls correctly, there will be a bunch of vacuum lines about a 1/4 inch wide that run from many of the controls to small valves that move different flaps in the heat and air unit. As those flaps move it does all kinds of things like move flaps to different positions to direct flow up to the windshield, down to side vents, or to the floor.
If those flaps don't move in the right way, the whole things may do odd things!
Things like the valve which cuts off hot water flowing through the unit may not move and you can wind up with both heat and air conditioning being done at the same time and that sounds like what you may be telling us??
A simple look at those small vacuum lines may show them to be old, dry, and brittle. If you bend them and see cracks, there is a good chance it is time to change those tubes as they often get cracks that leak vacuum at times when there is not a large vacuum being provided by fast engine speeds!
Usually not a high tech, complex thing as they often are just stuck on the fittings and can be pulled off and the tubing is very common and pretty cheap to replace.
If you want to DIY, this might be a cheap, simple thing to do as a starter?
One point to be careful on is that the plastic fitting can also get brittle as they age, so a bit of gentle is good to avoid breaking the end off the fittings!
kathybug
New Member
Im sorry I dont explain well. The air is cold and blowing out of front vent, but when moving at thr slightest hill it stops blowing from front vent and mobes to defrost or floor. Sitting still works great. Tjanks
RayIN
Senior Member
Sounds like a vacuum leak to me. When vacuum level decreases the vacuum air blend doors default to defrost position.
Morich
Senior Member
Under the hood at the from of the RV, there will be a bunch of small black tubes about 1/4 inch think. Those are vacuum lines which use vacuum from the engine to go to different places on the heater and air conditioner. As those get older they get hard and brittle and begin to leak.
When they get old enough they can get cracks along the side of the lines or where they connect to other parts.
That vacuum is what moves the different flaps/doors to change where the air moves. When the engine works harder or different speed, that vacuum changes, so it can work at one time and stop other times.
The tricky part is finding where that leak is on so many lines and places it might leak.
One idea that you might be able to spot? The front/forward side of the heater/ air conditioner is often a big black cover that sticks out under the hood. Normally at eh left side as we look under the hood? Someplace along the edges of the big black cover, there is likely to be an odd looking valve sticking out that has one of the rubber vacuum lines on it.
Something like this?
there are likely to be two of these on the black box cover. Each controls a different door inside the box and those doors need to open and close at the right time to make the air move in different directions, up to the windshield or down to our feet!
One small thing to check is pulling the tubing off and feeling with a finger for vacuum sucking on your finger! When there is vacuum there, it moves a rod sticking out that connects to a handle on the door which is inside where you can't see it.
It sounds like there is enough vacuum at times to move the flaps but at different motor speeds that vacuum may not hold the flap in the right place.
When they get old enough they can get cracks along the side of the lines or where they connect to other parts.
That vacuum is what moves the different flaps/doors to change where the air moves. When the engine works harder or different speed, that vacuum changes, so it can work at one time and stop other times.
The tricky part is finding where that leak is on so many lines and places it might leak.
One idea that you might be able to spot? The front/forward side of the heater/ air conditioner is often a big black cover that sticks out under the hood. Normally at eh left side as we look under the hood? Someplace along the edges of the big black cover, there is likely to be an odd looking valve sticking out that has one of the rubber vacuum lines on it.
Something like this?
there are likely to be two of these on the black box cover. Each controls a different door inside the box and those doors need to open and close at the right time to make the air move in different directions, up to the windshield or down to our feet!
One small thing to check is pulling the tubing off and feeling with a finger for vacuum sucking on your finger! When there is vacuum there, it moves a rod sticking out that connects to a handle on the door which is inside where you can't see it.
It sounds like there is enough vacuum at times to move the flaps but at different motor speeds that vacuum may not hold the flap in the right place.
Yeah that's a vacuum leak. One of the vacuum lines controls the inside/outside blend door, and another probably controls the AC/Defrost door. I replaced my lines in my 2006 Class A. You can do that by cutting out the bad part, taking it to the auto parts store, and getting a length of the tubing that is wider and will basically slip (tightly) over the original tube. Then splice it. Cheap fix. Those old lines rot. I have also heard that critters like them because there is some plant protein used to make them.
The problem is a malfunctioning vacuum reservoir. The easy fix is to install a reservoir under the dash on the passenger side. It is an easy 1 hour job to do and the parts are not expensive. I had the exact same problem and I did this fix on my 2004 WB and now the air conditioner continues to blow out the front vents even when under load. There are a few YouTube videos for this repair. Hope that helps.
RayIN
Senior Member
I've "repaired" vacuum reservoir leaks by cleaning them off and spraying them with lacquer; doesn't work for the hose though.
S.Rodimus
Senior Member
- Joined
- Dec 4, 2023
- Posts
- 126
I have a similar problem on the same chassis. It wasn't until I came across this little blurb in Wildsam magazine that I learned it was a vacuum leak.
If you're not a Do-It-Yourself-er, You don't need an RV service center to address this.. Just bring it to a Ford mechanic or a general truck mechanic who knows how to deal with A/C issues.
If you're not a Do-It-Yourself-er, You don't need an RV service center to address this.. Just bring it to a Ford mechanic or a general truck mechanic who knows how to deal with A/C issues.
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