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Dash air failing to cool

Yahoo Message Number: 78289
My dash A/C is blowing fine but no longer providing cool air. The same thing happened a year ago. I had the system re-charged and it worked fine for several months.
I suspect I have lost coolant due to a leak somewhere. Is this something that I can trace myself? Perhaps a loose or bad fitting? I know that I can charge with coolant that has a dye included. But, where do I start looking for the leak(s)? Daron Hairabedian, 98 Allure, 30226

Re: Dash air failing to cool

Reply #1 –
Yahoo Message Number: 78290
If you put a dye in your system you'll need a black light to look for it. Just hope that the leak is not in the evaporator coil. It is a bear to get to.

Steve & Jane

1998 Intrigue

#10557

______

Re: Dash air failing to cool

Reply #2 –
Yahoo Message Number: 78292
Daron, the system also uses ester oil lubricant to keep the compressor healthy. Quite often this will stain the hoses and fittings when the freon escapes, look around the hoses and fittings for oily stains. When our condenser cracked just past the inlet, the leak was obvious and a repair without replacing it was possible. Then add oil and recharge with freon and dye to check for future leaks? Good luck.....Skip 2002 Intrigue #11329

Re: Dash air failing to cool

Reply #3 –
Yahoo Message Number: 78293
The oil will show up on the high pressure side of the system. If there is no oil then its most likelyon the low pressure side. A lot of times its a loose connectionat the compressor. It gets the most vibration there.

Steve & Jane

1998 Intrigue

#10557

______

Re: Dash air failing to cool

Reply #4 –
Yahoo Message Number: 78303
We' had the same experience..... finally gave-up on dash-air as it was only barely adequate anyway. Now we simply run the genny while underway and keep the A/C going. Way better.

Cheers, Mel Shapiro
'03 LEXA

Re: Dash air failing to cool

Reply #5 –
Yahoo Message Number: 78304
Mel's plan is my plan too.

Two prior fixes, two prior bills, two failures . . . no more.

Lee
--

Lee (leozbrowski@...) 2007 Country Coach Intrigue 12153
CAT C-13

Re: Dash air failing to cool

Reply #6 –
Yahoo Message Number: 78311
Daron,

There are a number of things you can do to possibly narrow down the problem. However, depends on how much you want to dig into the system and how much you want to invest in $$$ to repair. Especially for a system that is marginal at best to provide cooling in the coach. While, I still use my OTR AC, on really hot days I run the generator and roof AC.

Here are a few ideas you can consider:
Do you know if your compressor clutch is engaging and compressor is running? With engine running and AC turned on to MAX COOL, look at the center of the pully on the compressor. If the center is turning, then there is still a sufficient freon charge in the system. If the freon charge has leaked down the center of the pulley will not be turning or will be cycling on and off. There is a lower pressure switch on the accumulator that will disengage the clutch if the pressure is too low in order to protect the compressor. A cycling compressor clutch indicates there os still some remaining freon in the system. A compressor clutch not turning at all may indicate that all freon has escaped.
Has your coach been in storage without occasionally running the AC? If so, most likely you have a leak at the compressor. If you use your coach and AC with little storage time, then look at your compressor around and behind the pulley/clutch for any signs of oil. Compressor will leak if not occasionally used. Especially, those 14 years old.
Other areas of common leaks are the schrader valves in the servicing ports, fittings at the compressor and accumulator as well as the evaporator. The hoses run from the rear of the coach all the way to the evaporator at the front of the coach. Hose can chafe anywhere along the way resulting in a leak.
If you have no evidence of oil leakage and there is residual freon pressure, try some soap and water or get it serviced with some dye so you can find the leak with a black light. Some leaks may only show up only after running the system for several hours or more. If you have evidence of an oil leak, then you may need more refrigerant oil as part of the charge. If you have no freon pressure on the system, then the entire system needs to be pressurized to determine leak down rate. If the system is empty, some techs will use a static load of dry nitrogen, gauges and a sniffer to verify leaks.

Jim Hughes

2000 Allure #30511

Re: Dash air failing to cool

Reply #7 –
Yahoo Message Number: 78335
I have an 04' Allure. Dash air went hot only. In the front of yor coach there are two electronic dispensor valves that direct the either heat or
cold air to function. Replaced that valve and all is OK. Clamp off the hot water hose and then try the air conditioning.

Re: Dash air failing to cool

Reply #8 –
Yahoo Message Number: 78341
Recently, my dash air/heat/vent just stopped functioning - I heard a bit of a sound coming from behind the dash as if it was trying to work. I had no heat, a/c, no vent.
Not knowing very much at all about these things, I stopped at a repair place. It took them 10 minutes to "fix" my problem - it was a blown fuse. Now I need to find out where I would look to check this should it happen again so I can save myself time and money...... big learning curve here for me..... jan

06 Inspire DaVinci 51898

Re: Dash air failing to cool

Reply #9 –
Yahoo Message Number: 78364
Jim,

Thank you for your very comprehensive response. I tested the system a couple of days ago with a thermometer stuck into the A/C outlets in the drivers area with the fan set at low and the selector set at MAX COOL. The ambient outside air temp was @ 84 deg. F. After running the A/C for about 20 minutes, the thermometer read about 58-60 deg. I have been advised previously that this should read out at around 42 deg. F. Is that correct? Tomorrow I will inspect compressor while it is in operation per your instructions. Then, I will report my observations.
Daron

Re: Dash air failing to cool

Reply #10 –
Yahoo Message Number: 78365
If you are getting 58-60 deg sounds like you may need to add some refrigerant (R134A)

Steve & Jane

1998 Intrigue

#10557

______

Re: Dash air failing to cool

Reply #11 –
Yahoo Message Number: 78366
Isn't 20 degrees below ambient about all you can expect for temp. drop?

Dave

aka Billy Byte (trusty hound)
2000 Allure #30443

Re: Dash air failing to cool

Reply #12 –
Yahoo Message Number: 78373
No. A properly operating automotive system with 134a refrigerant will do far better than that. To prove it to yourself simply put a thermometer in the outlet in your car. You'll find that it blows cold in any ambient temp.
My 2004 Allure, when set on A/C bringing in 95 degree outside ambient air, while cruising down the road, will blow at or below 50 degrees depending relative humidity.
Check your car and verify. Your coach is capable of the same performance as the system is the same.

George in Birmingham
'04 Allure 31038
George in Birmingham
2003 Magna 6298

Re: Dash air failing to cool

Reply #13 –
Yahoo Message Number: 78392
Sounds like your system has some freon in it but it may not be enough. You will likly notice your compressor cycling on & off. The low pressure switch usually cuts it off at 20psi and then on at 45psi. Your air temp should be 40-45f with system in MAX COOL, fan on high and engine @ 1000rpm.

Jim Hughes

2000 Allure #30511

Re: Dash air failing to cool, follow up.

Reply #14 –
Yahoo Message Number: 78472
To Jim Hughes and all others who responded, Thank you. I got a great education here.
Follow-up report.

Upon inspection I observed that the clutch was cycling. All hoses seem to be in good condition and properly secured. No evidence or chaffing. Yes, the coach has been in storage for several months in S. CA.
I was able to have an auto tech friend check it out. He has the proper gauges and fill system. When he removed the dust covers he advised me that one of the valves showed evidence of leakage into the dust cap. We cleaned the cap and he snugged up the guilty valve. Then, he proceeded to add about two canisters of refrigerant as he monitored the gauges. He advised that the valves should be replaced but that the freon would need to be recovered with shop equipment.
Success! Temp at outlets went down to 44 degrees at 700 RPM. I will monitor performance over the next several months during our summer trip.
BTW, in our experience, the dash air has been adequate to keep both driver and co-pilot comfortable most of the time. I do not believe that there is any appreciable sacrifice in fuel economy with the dash air on. On the other hand, I have been told that the gen-set drinks between .5 to .75 gallons per hour on my coach......But, that subject has been covered before.

This group is such a wonderful asset. Thanks again to all! Daron Hairabedian, 98 Allure 30226

Re: Dash air failing to cool, follow up.

Reply #15 –
Yahoo Message Number: 78486
Daren,

Glad you were able to find the problem and get working. Now your coll going down the road. Safe travels.

Jim Hughes

2000 Allure #30511

Dash air failing to cool

Reply #16 –
Yahoo Message Number: 78367
You will only get at best 20 degree delta, so if the air coming in is 80 degrees only 60 degrees will come out.

Dave

Dave Rousey Jr./ Owner
Former CC Technician
Styleworks RV Repair &
Restoration LLC
4762 Long St.

Sweet Home, OR 97386
(541) 543-7983

http://styleworksrvrepair.com dave@...

Re: Dash air failing to cool

Reply #17 –
Yahoo Message Number: 78374
That is not true Dave. A properly functioning 134a system will blow cold in any ambient temp once you are cruising down the highway. To verify this check the temp at the vents in your car. My coach dash A/C works extremely well. I don't need to run generator and rear roof A/C below 100 degrees ambient if dry and 95 degrees if humid. I do, however, have a short coach so larger coaches will have different results.
I do have clamps on hot water lines to the chassis HVAC heat exchanger. I have found that this makes a big difference to A/C performance.

George in Birmingham
'04 Allure 31038
George in Birmingham
2003 Magna 6298

Re: Dash air failing to cool

Reply #18 –
Yahoo Message Number: 78376
I'm not an expert, but I think Dave has it right. If your temp drop is around 20 degrees that is a good drop and what you hope for.
If your coach is more than 20 degrees cooler than outside air, its probably because the air conditioning is set to recirculate inside air.

Jim

2005 Inspire#51225

Re: Dash air failing to cool

Reply #19 –
Yahoo Message Number: 78377
Not true Jim. The only time I run the dash air on recirc is when it is so hot (over 95) that I need to run the rear roof A/C. I otherwise bring in fresh air and see temps below 50 at the outlet. Test you car system and see what the results are.
This 20 degree difference story has been circulating for years and is simply not correct. I guarantee that your car will cool ambient air FAR more than 20 degrees and the system is identical to the coach.
I'm not and expert either but I do know how to stick thermometer in my dash vents and read the number. The reason I suggest you test the 20 degree theory on a car is that those systems run reliably while coach systems not so much so.

George in Birmingham
'04 Allure 31038.
George in Birmingham
2003 Magna 6298

Re: Dash air failing to cool

Reply #20 –
Yahoo Message Number: 78378
George, you are probably right. I guess I might be remembering the 20 degree drop from when I had a problem with our house air.

Jim

2005 Inspire

Re: Dash air failing to cool

Reply #21 –
Yahoo Message Number: 78379
Working on A/C systems since the early 90's , a good running unit will have 16-22 degree split (delta) between supply & return. Rule of thumb....
Here is a quick link I pulled up on Google for A/C temperature differential... It's for residential but the basics are the same..

Testing

Re: [Country-Coach-Owners] Re: Dash air failing to cool

Reply #22 –
Yahoo Message Number: 78380
Thanks, good find I was looking for my data sheets but this will work.

Dave

Dave Rousey Jr./ Owner
Former CC Technician
Styleworks RV Repair &
Restoration LLC
4762 Long St.

Sweet Home, OR 97386
(541) 543-7983

http://styleworksrvrepair.com dave@...

Re: Dash air failing to cool

Reply #23 –
Yahoo Message Number: 78381
Jim, I think you are exactly right.
Home systems are not designed to handle the extreme temps that we see in our cars. A 20 degree drop across a home system evaporator seems about right. It works because it is always drawing from the inside air rather than bringing in fresh air.
We've all come home from trips during which we have set the thermostat up. The amount of time it takes to catch up to the higher temps would be unacceptable to us in our cars.
My only point in gnawing on this is that, when properly functioning, our coach chassis A/Cs work exceptionally well.
For those who feel their dash A/C works, but not well, I suggest the first thing to do is clamp off the heater hoses to the heater core. It made a substantial difference for me.

George in Birmingham
'04 Allure 31038
George in Birmingham
2003 Magna 6298

Re: Dash air failing to cool

Reply #24 –
Yahoo Message Number: 78382
Jim,

Your reference is to a home HVAC system. That is a completely different animal than an automotive system.
Below is a short comment from an A/C expert regarding the same issues.
"One can't really claim a number for all ambient temps. The hotter the ambient(air entering evaporator) the greater the heat(temp removed from it going through the evaporator. This is just newtons exponential law of cooling at work. So yes possible to see 50F drop across the evaporator at ambient of 100F, but if ambient is 70F, this same drop wont happen. The other factor is the vaporisation temp of the refrigerant, its not infinitely low either.
House aircons typically dont do as well as car ones in terms of temp reduction across the evaporator, just design. They arent having to cope with 130F interiors when left in the sun etc."

George in Birmingham
'04 Allure 31038
George in Birmingham
2003 Magna 6298