Dash A/C vs Max Air Setting Question 2008 Sightseer 29R

[Morich]

Question for the group to check what I might remember? Am I right in thinking the max is just recirculated air and the other is outside air?

[7997redtail]

When I switch between ac and ac max I can watch the door open and close.

I’ve heard someone say not to run in max mode all the time but I’ve never heard a good reason not too.

It’ll be interesting to hear from someone that could confirm either way.

[Bones2003]

The next steps you could try is to start with a cold engine and cold hoses.
1) Set the temp control to cold (blue zone) and the function control to Max AC.
2) Start the engine and let it warm up. You said Max AC works fine so I expect the hoses by the valve should stay cold/cool because the valve stays closed.
3) Once things have stabilized, set the control to regular AC. If the hoses start to warm up after a bit, then the valve has opened but it should not. This would indicate a fault in the green vacuum line to that valve.

Can you trace that vacuum line from the valve? If it goes directly to the function controller then the controller may have a problem. It it goes to some other intermediate device like a vacuum switch then that might be the problem.

Another thing to keep in mind is that on regular AC, the recirculate door is open so the AC sucks in a lot of heat that is just blowing off the engine. That is why many people notice the AC works fine while they are moving but not so much when they are stopped at a red light. If this is happening during testing, you could setup a box fan to blow the engine heat away from the AC unit.

[7997redtail]

Sounds good. I think the hockey game is going to be starting up soon so I will do this tomorrow. Beside, we've had some wicked storms go through today. A good day to watch sports.

Thanks

[Morich]

One of the things I notice is how many people like to warn new folks about things that might or could happen!
Manuals for new cars are a place where they seem to overwork the idea on moving fresh air into the car.
If you are so hot and sweaty and there windows are all steamed up from too much moisture inside, switch to fresh air by going off the max setting!
We do not worry that too much and if it is a hot day or we are in traffic where we don't want to suck in the city fumes, we leave it on max!
On nice days when out in the country, we may go to fresh air as it smells nice but it's not something we worry too much.
If there are four cigar smokers in the car, don't stay on recirculated air if you have trouble breathing!

You can get the car colder on max but that is because you are passing the same air over the AC instead of trying to cool the hot outside air it's bringing in!

I'm guessing you'll know when you need fresh air??

[7997redtail]

“ If there are four cigar smokers in the car, don't stay on recirculated air if you have trouble breathing!”


think my brother, a cigar smoker. Would disagree. Particularly if it was an expensive cigar. He could keep breathing it in and out.

Very good points otherwise.

Sorry 2-0 Edmonton. My guess is management got together. Floridas going let Edmonton have one game then Florida will finish it off at the next game. Can you imagin how much the NHL Makes in beer, food and clothing sales each game?

[7997redtail]

Bones, I got it done. On max ac the pipes are cold. Once switched to just AC the pipes get warm. Therefore, the valve is working but opens when it shouldn’t. In just AC the valve should not open.

Thanks for the trouble shooting matrix. I’ll start looking for piping diagrams to see if the pipe goes directly to the valve or goes through something on its way.

Any advice on how to disconnect the tube from the valve?

Thanks again and hope you had a great Father’s Day.

[7997redtail]

I found this interesting. If you look at the attachment then “rotary valves” which I have the recirc. valve is only closed in max ac. The OP suggests he is going to reprise so the valve is also closed in AC.

https://www.irv2.com/forums/f101/das...am-200700.html

[7997redtail]

I just went back to look for more info. I think I should take morichs advice. Start smoking cigars and not worry about having it on max ac all the time.

[7997redtail]

That’s interesting. On the original thread I thought I had finished off with deciding to smoke cigars. . I don’t think this is the complete thread.

So FYI, I decided to leave this situation as is. I get cool to warm air in AC mode because ford runs a recirculation valve open (hot engine coolant going through AC unit) in all modes but AC Max. Everything I read says there is nothing wrong with running AC Max all the time. Except, as was pointed out for cigar smokers, you would be recirculating the cabin air.

Thanks to the help from those above we proved the valve was doing what it supposed to.

The cigar comment comes from

[Morich]

There are times when things do seem to go missing and I have never figured it out! One way that can happen to me is when I get something written up to post and then get a call, etc. and forget to hit the right button to post!
But the computer world is part of the reason we have so many crazies around, so it is possible the internet is just playing tricks on us??
How would we ever know if the Russians or Chinese were attacking? I get pretty much the same results every Weds. when Microsoft does their update!
I'm often blown up for a while until I figure what they have done to me!

[bigb]

Originally Posted by 7997redtail

That’s interesting. On the original thread I thought I had finished off with deciding to smoke cigars. . I don’t think this is the complete thread.

So FYI, I decided to leave this situation as is. I get cool to warm air in AC mode because ford runs a recirculation valve open (hot engine coolant going through AC unit) in all modes but AC Max. Everything I read says there is nothing wrong with running AC Max all the time. Except, as was pointed out for cigar smokers, you would be recirculating the cabin air.

Thanks to the help from those above we proved the valve was doing what it supposed to.

The cigar comment comes from

The only thing I've noticed about using recir all the time is sometimes you will get a musty odor. When it's over 100 here I use recirc as it is colder and less work for the system, but I try and limit the length of time on recirc. It also varies by vehicle. On my Ford F350 it's not bad but noticeable, on my VW TDI it can get pretty bad, like old socks when you first start the AC. What I like to do with that one is kill the compressor for the last couple minutes and blow fresh outside air thru the evaporator to dry it before shutting down, helps a lot. I used to have a Grand Cherokee and it was the worst, terrible odors when using recirc. I ended up making a 1/2" hole in the evaporator housing and once a month I'd put the garden hose sprayer against the hole and rinse it all out.

I guess there's a reason some German cars time out on recirc after 20 min and go to fresh air.

[Ray,IN]

Originally Posted by 7997redtail

I checked and my ac has SCS in Fort Worth Texas on a label. I was just going back to the site link that worked yesterday but doesn’t today. Humm. Only active on weekdays?

Reasearch says they are bankrupt.

This document might be what you need then: http://www.rialtainfo.com/winnebago/...003-02-02a.pdf
If your vacuum harness needs replaced: https://www.comfortairgr.com/product...ory-036-00533/

[Ray,IN]

Originally Posted by bigb

The only thing I've noticed about using recir all the time is sometimes you will get a musty odor. When it's over 100 here I use recirc as it is colder and less work for the system, but I try and limit the length of time on recirc. It also varies by vehicle. On my Ford F350 it's not bad but noticeable, on my VW TDI it can get pretty bad, like old socks when you first start the AC. What I like to do with that one is kill the compressor for the last couple minutes and blow fresh outside air thru the evaporator to dry it before shutting down, helps a lot. I used to have a Grand Cherokee and it was the worst, terrible odors when using recirc. I ended up making a 1/2" hole in the evaporator housing and once a month I'd put the garden hose sprayer against the hole and rinse it all out.

I guess there's a reason some German cars time out on recirc after 20 min and go to fresh air.

Try introducing Hydrogen Peroxide into the A/C drain pan.

[Ray,IN]

Of course the solution to the heater hose valve being open except when Max air is selected is to install a manual shut-off valve in the heater hose prior to the heater coil. Auto owners have been doing that for nearly a century.
On the opposite side, I can remember when running the heater when climbing a hill was the best way to prevent engine overheating.

[7997redtail]

Thanks for the info. I found these earlier and I think it was on C2 that it shows the circulation valve open when I don’t want it open.

As for putting a shut off in? It’s discussed earlier. I’m just going to run max ac.

[bigb]

This reminds me of the Superduty Cold AC mod kit, a lot of Superduty owners have installed it. Seema to be more of an issue on the pre-2002 models though, I never needed it on my 2002. https://www.dieselsite.com/colderacvent.aspx

One thing to note, if any mod is done that stops coolant flow completely it's a good idea to occasionally open it and let the coolant in the heater core change out otherwise it gets stagnant and acidic. This is the reason we were told that the coolant is allowed to tricle thru the heater core.