Community Forums

dorisk1122 · 08-10-2016, 04:34 PM

Dash A/C just blowing air -- not cooling. Thinking it might be the thermostat but can't seem to locate it on our 2013 Phaeton QBH

BFlinn181 · 08-10-2016, 05:03 PM

On the dash HVAC controls, temperature is set by a knob or slider. Is there a button too turn on the A/C? The temperature sensor is buried in the plenum, the box with the heater core, fan, and evaporator. Have you checked that the compressor is engaged when the A/C is turned down? There's a low pressure cut-out switch that stops the compressor from engaging when refrigerant is low. There's also relays that have to work properly, and other things that could be preventing the A/C from coming on.

dorisk1122 · 08-10-2016, 06:10 PM

Thanks, we'll check that out.

Snyderwheels · 08-21-2016, 11:03 AM

If the last response didn't work check the AC dryer. On my 2013 Allegro RED it is located in the front generator compartment on the passenger side.

I had this problem on my coach and took it to a local RV place for repair. They removed the dash and spent about 12 hours trying to diagnose the problem but couldn't figure it out. Fortunately, they didn't even ask me to help cover their costs. I stopped by Red Bay the next month and their tech took less than 5 minutes, probably more like three, to figure it out.

Stang · 08-31-2016, 08:31 AM

I had many folks tell me the dash air doesn't do much in terms of cooling. Mine wasn't working either and while I'm sure you've already thought about it...I added some 134 refrigerant and mine works pretty well...at least for the two up front passengers.

Stang

IFlyABus · 09-01-2016, 01:52 PM

Check to make sure your compressor is spinning when you turn the A/C on. Might look at it first with it off, then compare to on (if you are unfamiliar with how a automotive compressor functions). If it doesn't engage, your freon is low.

BFlinn181 · 09-01-2016, 05:19 PM

Quote:

Originally Posted by IFlyABus

Check to make sure your compressor is spinning when you turn the A/C on. Might look at it first with it off, then compare to on (if you are unfamiliar with how a automotive compressor functions). If it doesn't engage, your freon is low.

The compressor clutch might not be energized for a number of reasons besides low refrigerant pressure. The thermostat could be bad, as OP thought, a relay could be bad, a wire could be disconnected, a fuse could be blown. It's not always low on refrigerant. (Freon, is a Dupont ™ product not in use since the mid '90's)

IFlyABus · 09-01-2016, 08:15 PM

Pretty sure everyone knows what is meant when a person says "freon" in regards to an air conditioner topic. A lot simpler than typing Tetrafluoroethane, eh? But thanks for the clarification!

BFlinn181 · 09-01-2016, 10:21 PM

Quote:

Originally Posted by IFlyABus

Pretty sure everyone knows what is meant when a person says "freon" in regards to an air conditioner topic. A lot simpler than typing Tetrafluoroethane, eh? But thanks for the clarification!

It does make a difference and it's as incorrect as calling every copy machine a Xerox or every facial tissue a Kleenex.

Actually, Freon-12 is Dichlorodifluoromethane and there are a number of types of Tetrafluoroethane, the common version in auto A/Cs is 1,1,1,2-tetrafluoroethane.

I wouldn't have corrected your posting if you hadn't stated, "If it doesn't engage, your freon is low." Is I pointed out, there are numerous reasons an electric clutch might not engage, I didn't include all of the possibilities, just 4 of the more common issues. There are even more, I just couldn't allow your statement to stand as if it was the only possible thing that it could be.

I get frustrated with many responders on here that had a repair of an item on their RV and they share the experience as if it's the only solution to problem. RVs have complex systems and there can be many other reasons for something to fail. I always try to suggest simple (if possible) tests to figure out the reason something failed, the cheapest solution first. Throwing money at a problem is fine for those that can afford it, but I was raised and have always done as much as I can to explore the problem so I don't get smoke blown my way and unnecessary parts and labor get added into a repair I couldn't do myself.

When you just suggest adding refrigerant as the solution, you do a great disservice to the person with the problem. Adding refrigerant to a R-134a system is not as simple as just connecting a hose to the low pressure valve and adding a can of R-134a. This refrigerant is not as forgiving as the old R-12, too much can cause a lack of cooling as much as too little can. It's peak cooling efficiency is a narrow band of proper pressures. Use of a manifold set of gauges to monitor high and low pressures within the system, adjusted for ambient temperature, is really the only accurate way to recharge the system. How much oil should be added? If it leaked out, there's a bad seal or connection that should be found and corrected, or you'll just have to add more refrigerant down the road.

IFlyABus · 09-03-2016, 10:13 PM

Everyone in the US knows what Freon means as regards a topic about A/C. And most are probably aware that Freon, as marketed by DuPont.

The same way that people call those big, wooly-looking mammals in the US buffalo, when in fact they are bison. Buffalo do not exist in the US (did you know that?). But, we all know what is meant when someone says buffalo, right?

When I said Tetrafluoroethane, I was referring to R-134a, sorry you missed the point. Freon is simpler to type on a phone, and everyone will know what is meant, whereas so few will know what Tetrafluoroethane is.

Not saying you are wrong, because you are not. But on a public forum, people talk about what they know, and there are common terms that are well understood, though not quite as accurate perhaps.

As far as correcting my post, in 50 years of dealing with auto A/C systems, I have known several times where low FREON was the reason why a compressor would not engage. Is that the root problem? Of course not. A leak is. Once, in all those years, a bad compressor was the culprit. And not once, in all those years, was a fuse nor a loose wire the problem. So while there are SEVERAL reasons why a compressor may not engage, I listed the most common one IN MY EXPERIENCE. If it's not your personal experience, feel free to chime in as to what you have seen, and between us, I am sure we can help the folks who need it.

Whistle all you want, but my suggestion was one of the simplest ones of what commonly goes wrong with an A/C system.

Now, since you like to solve problems, please see my other post about my Xantrex LoadSense issue, and help me solve it!

Quote:

Originally Posted by BFlinn181

It does make a difference and it's as incorrect as calling every copy machine a Xerox or every facial tissue a Kleenex.

Actually, Freon-12 is Dichlorodifluoromethane and there are a number of types of Tetrafluoroethane, the common version in auto A/Cs is 1,1,1,2-tetrafluoroethane.

I wouldn't have corrected your posting if you hadn't stated, "If it doesn't engage, your freon is low." Is I pointed out, there are numerous reasons an electric clutch might not engage, I didn't include all of the possibilities, just 4 of the more common issues. There are even more, I just couldn't allow your statement to stand as if it was the only possible thing that it could be.

I get frustrated with many responders on here that had a repair of an item on their RV and they share the experience as if it's the only solution to problem. RVs have complex systems and there can be many other reasons for something to fail. I always try to suggest simple (if possible) tests to figure out the reason something failed, the cheapest solution first. Throwing money at a problem is fine for those that can afford it, but I was raised and have always done as much as I can to explore the problem so I don't get smoke blown my way and unnecessary parts and labor get added into a repair I couldn't do myself.

When you just suggest adding refrigerant as the solution, you do a great disservice to the person with the problem. Adding refrigerant to a R-134a system is not as simple as just connecting a hose to the low pressure valve and adding a can of R-134a. This refrigerant is not as forgiving as the old R-12, too much can cause a lack of cooling as much as too little can. It's peak cooling efficiency is a narrow band of proper pressures. Use of a manifold set of gauges to monitor high and low pressures within the system, adjusted for ambient temperature, is really the only accurate way to recharge the system. How much oil should be added? If it leaked out, there's a bad seal or connection that should be found and corrected, or you'll just have to add more refrigerant down the road.