Dash Air Conditioning Troubles

[dcatel]

I have a 2003 National RV 38 Ft Tradewinds on a Spartan Chassis, Cat 326 engine. Evans Tempco RV218467 Control Panel. For several years now the system loses its charge a couple of days after being recharged. The Compressor has been replaced; the dryer and I believe the expansion valve have been replaced. At least 3 different RV service outlets have worked on the problem. The system was flushed after the compressor was replaced. Each time the system is recharged with leak detector but the leak has not been found.

The last service organization said this was a common problem and that a number of customers just choose to either not attempt to find the problem or for very slow leaks just recharge the system every season. I want too resolve the problem once and for all, but don't want to spend another thousand dollars just looking.

Any ideas on how to cost effectively approach troubleshooting this problem. Or are some folks out there in the same boat, not able to use their dash air conditioning because of the potential expense of troubleshooting the system.

Thanks for any ideas.

[wolfe10]

Have them add a leak detector dye when they next work on it.

Our dash HVAC works just fine and is 19 years old. You will have to determine the fix the dash A/C ($$$) vs use generator and overhead air ($$$) based on your needs.

Here is a typical product: http://www.oreillyau...N1786&ppt=C0050

[BillO]

I've had the same experience with the dash A/C in my 17-year-old unit even though the major components were all replaced to upgrade to R134.

One tech pointed out that there is a lot of tubing (rubber, composite?) snaking from front to back in the DP's. If there is a leak along one of those lines there isn't any good way to see it even with the dye.

It seems to me that one could evacuate the system, disconnect those lines at the right point, plug them, then pressurize at the schrader valves to either isolate or rule out the lines as leak sources.

If the lines are the leak source, I'm not sure what to do as they are well buried in the coach chassis (at least in my case). However, you would at least know the cause.

If the lines prove not to be leak sources, then some more diligent work needs to be done around front and rear connections. One area that a tech found in my coach was a leaking weep hole on the high pressure connector to the compressor (that did not, however, solve my overall problem).

[campcop]

I've had the same experience with the dash A/C in my 17-year-old unit even though the major components were all replaced to upgrade to R134.

One tech pointed out that there is a lot of tubing (rubber, composite?) snaking from front to back in the DP's. If there is a leak along one of those lines there isn't any good way to see it even with the dye.

It seems to me that one could evacuate the system, disconnect those lines at the right point, plug them, then pressurize at the schrader valves to either isolate or rule out the lines as leak sources.

If the lines are the leak source, I'm not sure what to do as they are well buried in the coach chassis (at least in my case). However, you would at least know the cause.

If the lines prove not to be leak sources, then some more diligent work needs to be done around front and rear connections. One area that a tech found in my coach was a leaking weep hole on the high pressure connector to the compressor (that did not, however, solve my overall problem).

That was my idea as well, the leak is most likely in a line and not in a major component if all have been either replaced or leak tested..

[Icefixr66]

I have been told that the exsisting lines themselves leak due to the difference in molecular structure of r12,r22 and r134. Don't know how true this is but I have heard it from numerous people!

[dickandlois]

This problem has turned up on a number of the larger PU trucks and some cars. That for the most part do not use the flexible lines used on Coaches. Not to say it is not possible with all the effort spent on how to save another dime.

The one item I have found to leak and not show any sighs of the dye are the valves in the High and Low pressure monitoring and charging points.

That little Schraeder Valve, like on tires. In this case the seal color for AC systems is Green. A little different compound because of the heat and cold range of the different sections of the system. They leak so slowly that it takes weeks to even months to see the reduced cooling effect, and the green dye is trapped under the caps. Not a sign of it on the exterior of the cap.

So,if you clean this area vary well with,something like spray contact cleaner, after it has been vacuum pumped, dyed( DO NOT OVER DYE OR OVER OIL) and recharged to the proper point.

Clean the caps the same way,put them on and forget it for a few weeks.

Then remove the cap, where it is a little dark at least, (not out in the sun) and shine a UV light at the area. (Black Light) if it glows it is leaking.

Considering the cost to recharge the systems along with time to vacuum pump, and other items needed is it worth it?

Should you live in an area of the country where you get an extended cooler season,then just before the hot weather arrives and the AC is not working anyway.Replacing the valve core at the time gets the best bang for your buck.

I loose about 8 to 10 oz. of 134 in my truck over 12 to 18 months and 6 to 8 oz. in the Coach (Motorhome)over the same period of time at present.

If you do change the core section, clean things VERY VERY well inside the stem area and the seal of the valve core. The smallest leek and the charge will slowly drop. If there is the smallest flaw in the set area its not ever going to completely seal.Then to replace the section(s)with the valve,is it worth $$$. ?

When one gets real lucky with the proper torque and cleaning and you reach 24 to 36 months, Well done my friend, Well done.

R.M.

[dcatel]

Thanks to all who have replied. Certainly a couple areas that I need to check, which I do shortly. Any additional comments will be welcome.

Dave C

[five]

dcatel...the bottom line to all the discussion is that you have a leak...period, regardless of what the techs are saying. We had a car like that, drove us crazy, EVERY spring the A/C did not work. Bottom line, it was a very tiny leak.

[drakeygirl]

We have a 2005 Vacationer and the dash air went off and then once in a while came back on and then off and then on. Do not know what is causing this.

[hermanmullins]

drakegirl,

Bad switch, loose wire, faulty ground. Had same problem on my 98 Monaco and found the ground wire connector was loose, squeezed the connector a bit and problem was solved.

Herman

[montie]

I have the same problem. I have spent about $2000+ on Evan-Temcon. I have talked to them and Newmar. I was told the AC had a switch installed incorrectly, went to an Evan service center, they said they found the leak and replaced an $800 dollar hose, ordered it from Newmar. That lasted less than 6 months.

I finally took it to a local auto AC guy in town and he found another leak in the front compartment different place but when checked there was no leak in the front just in the back. He only charged $285, he put dye in the system just in case. The leak this time was in the evaporator coil, another $1000.

Now the new parts are at the dealer and they are to be installed next week before we leave on a two month trip. There was no leak in the coil the first two times. Then, the other leaks were fixed and all the sudden a big leak in the coil. I think that Evans tempcon should at least try to help but they were no help, just said it was not under warranty. I did not ask for warranty just someone that would give a little direction to find the problem. As most autos this coil is aluminum may be the problem, home ac's are usually copper for the most part. Anyway if I do ever trade again I will try to find a coach without Evans equipment, this is not the first time this has been discussed on the forum. I fully expect another leak at another place, These leaks are not hard to find, the one in the coil could be heard as soon as the gas went in, would leak out in just about one minute.You would think the first two times someone would have found a leak that big, make me think there is something wrong with the metal in the system.

[jbell]

Had the same problem on a 02 Allegro Bus. Made an appt. with Tiffin in Red Bay and the problem turned out to be the high pressure line that runs from front to back. Tiffin replaced the line, took 2 techs half the day. I was billed for the labor only still about 800.00. Unit has been working great.

[montie]

I am sure there is something causing the leaks. It has never had a leak in the same place. The first two the leak was on two different hoses and now it is in the front coil. The coil was checked the first two leaks then the third leak was in the coil. I had all three fixed but I am expecting another leak in a different place.

[waynem]

got a issue similar to all this discussion about dash ac problems.   I have a 2008 tiffin phaeton with about 70000 miles   the dash ac is not cooling  I put 2 lbs of r134 in it and leaked out over night.  so now im in a fix.     going  on trip and no ac in dash !!  ANY ONE OUT THERE HAVE A SUGGESTION   Iknow I can run roofac but don't really want to for lots miles. im in texas so its hot.   does anyone know the ac  systems on this particular motorhome   I would appreciate any info   

[montie]

I have had trouble with the dash aire in my 2009 Dutch Aire, I have replaced every major part and it still leaks down.  I have resigned to filling the freon every year, it will last about 3-4 months. I think it is a bad design but getting the AC company to agree is a problem.  There are a lot of people that are having a problem with the Evans-Tempcon system

[urbanhermit]

For general information, I learned this today:  We thought the dash air had started running any time the ignition was on and that we were getting no response at all from any of the three controls (FoMoCo products in our case).  Since diesels don't generate vacuum, there is a vacuum  pump somewhere, I suppose usually in the nose.  Two small hoses, as thin as 12-gauge wire, one white and one black in my case, connect to the flaps and whatnot that control air flow to feet, dashboard, and defroster vents.  If the black one (at least) is pulled loose from its nipple at the dashboard, or is punctured or broken, the vacuum pump will run continuously any time the ignition switch is on, and air will blow only through one set of vents.  In my case it's the defrosters.  The vacuum pump makes a noise like an air blower, which I though was the case until my coach mechanic explained things to me.  For a specific long-explanation reason I asked him only to disconnect electrical service to the pump until another mechanic checks the hose.